Ultrasound imaging in the hands of physical therapists: unlocking potential across specialties

Introduction

Ultrasound imaging is unique among diagnostic imaging methods because it allows clinicians to perform immediate point-of-care patient examinations. As a bedside technology, ultrasound has become an important tool in medicine for diagnostic, procedural, and screening purposes (1, 2). Its real-time imaging capability, diagnostic accuracy, portability, and ability to guide bedside procedures support rapid clinical decision-making and have made it a first-line diagnostic and interventional tool in many settings (3–5). Preliminary evidence also suggests that ultrasound imaging may reduce hospital length of stay and healthcare costs (6). Similar benefits may extend to physical therapy practice, particularly through improved clinical decision-making and practice efficiency.

The evidence supporting the diagnostic value across multiple areas of physical therapy practice continues to grow (7). Physical therapists are therefore positioned to incorporate ultrasound as an extension of the physical examination (8).

However, adoption remains limited. In an international survey of 1,307 physical therapists across 49 countries, only 18% reported using ultrasound imaging for diagnostic purposes (9). Because of potential self-selection bias and unknown non-response rates, the authors noted that actual use may be even lower.

Diagnostic ultrasound imaging is within the physical therapist’s professional scope of practice. In 2009, the American Physical Therapy Association House of Delegates adopted “Diagnosis by Physical Therapists” (HOD P06-12-10-09), stating that, “When indicated, physical therapists order diagnostic tests/studies, including but not limited to imaging and laboratory tests. Physical therapists may also perform or interpret selected imaging or other tests/studies.” (10). In 2016, the House further resolved that APTA pursues practice authority for imaging referral in physical therapy practice, supporting physical therapists’ administration and interpretation (11). Jurisdictional scope of practice is governed by state-by-state practice acts or board rulings. Most states do not prohibit ultrasound imaging, and many authorize physical agents –or measures for both evaluation and treatment. To date, 17 state practice acts or board rulings have specifically stated that ultrasound diagnostic imaging is within the physical therapist’s scope of practice (12). Only one state does not allow interpretation of ultrasound findings. In other states, practice boundaries remain unclear. In other states, there is no stated prohibition or authorization, and the boundaries of practice are unclear. The global variability in the physical therapy scope of practice mirrors the variability in the USA.

Survey studies also demonstrate substantial variation in physical therapists’ use of ultrasound worldwide. Ellis et al. surveyed 1,307 respondents from 40 countries and reported clinical uses including biofeedback, diagnosis, interventions, research, and teaching (9). In developed countries, published data suggest increasing use; for example, one in six physical therapy practices in the Netherlands offers diagnostic ultrasound (13). However, evidence from many countries remains limited, and low- and middle-income countries face substantial implementation barriers (14).

Despite its professional scope and growing indications for clinical use, relatively few physical therapists have the training and skills needed to perform ultrasound imaging in practice. In the United States, barriers include limited awareness, lack of standardized educational pathways, reimbursement limitations, and equipment costs. The Centers for Medicare & Medicaid Services recognizes physical therapists as qualified providers for certain diagnostic tests, including EMG, NCV, and SEP studies, but does not include physical therapists as qualified reimbursable healthcare providers for ultrasound imaging (15). Reimbursement is determined by the provider’s scope of practice as defined by the applicable state practice act, along with the provider’s education and training. This may include the Registered in Musculoskeletal Sonography (RMSK) credential or other advanced training in musculoskeletal ultrasound, provided the individual is qualified to perform and interpret the examination within their scope of practice (16). In addition, ultrasound has inherent limitations and may not be the preferred diagnostic modality depending on the anatomical region, suspected pathology, patient habitus, or operator skill. Evidence-based guidelines should guide imaging modality selection according to clinical scenario and pathological condition (17–19).

The purpose of this narrative paper was to summarize the strength of evidence supporting the clinical utility of point-of-care ultrasound imaging across various physical therapy practice areas. Because this was a narrative review paper rather than a systematic review, the authors cited both well-known studies and high-level evidence identified through a comprehensive PubMed search. The search focused on systematic reviews published within the past 15 years that examined the diagnostic accuracy of ultrasound findings relevant to physical therapy. Additional studies were identified by reviewing reference lists and using PubMed’s “Similar articles” feature. Generative AI was not used to produce, analyze, interpret, or substantively revise the scientific content of this manuscript. Chat GPT was used to improve clarity, grammar and readability of the manuscript. As understanding of ultrasound imaging applications continues to develop, physical therapists may be positioned to use ultrasound in selected clinical contexts, to support patient examination, diagnostic reasoning, and treatment planning.

Musculoskeletal ultrasound imaging

Bone and joint injuries and pathology

Musculoskeletal disorders affect over 1.71 billion people globally and impose substantial health and economic burdens (20), highlighting the need for effective diagnostic strategies (21, 22). For physical therapists, integrating point-of-care ultrasound (POCUS) imaging into the clinical examination can enhance diagnostic accuracy, improve patient management and strengthen understanding of clinical anatomy and examination skills (21). In musculoskeletal physical therapy, ultrasound can extend the physical examination by providing real-time visualization of tissues that may be contributing to pain, impaired movement, reduced loading tolerance, or delayed recovery. Musculoskeletal ultrasound can be an alternative diagnostic technique for examining bone injuries. Ultrasound does not use ionizing radiation, such as x-rays, making it safer imaging, particularly in the pediatric population (23, 24). Ultrasound is highly sensitive to bony changes and can demonstrate occult fractures that may go undetected by previous x-ray examinations (25). This allows physical therapists to more confidently refer when fracture is suspected. There are limitations and pitfalls to musculoskeletal ultrasound, which include the inability to see deeper than the bony cortex, typical bony abnormalities that mimic fractures and nuances in the early phase of stress fractures for non-expert sonologists (25).

Musculoskeletal ultrasound findings in various bony injuries include (25): Sonographic evaluation of extremity bone fractures not involving joints is comparable to radiographs. Pooled data demonstrate high diagnostic value in detecting extremity fractures, including pediatric upper extremities (Table 1). In a sports environment, ultrasound currently has limited value as a screening tool for repetitive stress-related bone injuries (Table 1) (26).

• Impact fracture: Focal interruption of the bony interface at the site of fracture or step-off deformity
• Avulsion fracture: Cortical bone detachment at the site of tendinous or ligamentous attachment
• Stress fracture: Hypoechoic (moderate brightness) thickening of the periosteum over the hyperechoic (high brightness) cortical bone, accompanied by edema of the surrounding soft tissue.
• Fracture healing: Stages of healing can be observed with ultrasound, including anechoic (no brightness) to hypoechoic hematoma at the fracture site in the early phase of echogenic calcific callus formation.

Table 1. Bone fracture and joint pathology.

MRI, magnetic resonance imaging; CT, computed tomography; CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; OR, odds ratio; NR, not reported.

Ultrasound imaging in joint pathology or degenerative disorders

Osteoarthritis affects an estimated 250 million people worldwide and is a major cause of disability, with prevalence expected to rise due to aging populations and increasing obesity rates. It accounts for 3.9% of global years lived with disability and represents a substantial economic burden, consuming 1%–2.5% of gross domestic product in high-income countries through healthcare and productivity costs (27). Joint diseases, such as osteoarthritis, involve structural alterations in joint cartilage, bone, ligaments, capsule, synovium, and periarticular structures, which can be observed on ultrasound (Table 1) (28). However, there are limitations, such as the inability to visualize the entire joint cartilage and intrinsic bone abnormalities.

Musculoskeletal ultrasound findings seen in joint degeneration or arthritic conditions include: Ultrasound imaging confirmation of knee joint effusion is reported to be superior to clinical tests (31). The sensitivity and specificity of ultrasound in identifying knee effusion are 0.84 and 0.93, respectively (Table 1). This added objectivity can improve a physical therapist’s clinical reasoning, particularly when determining exercise dosage, joint loading strategies, and need for referral. By identifying effusion, synovial change, or periarticular tissue involvement, ultrasound may help physical therapists better match interventions to the irritability, stage, and mechanical demands of the involved joint. In patients with adhesive capsulitis, capsuloligamentous thickness measures from ultrasound correlated with clinical measures of passive range of motion and pain (32). However, clinical measures did not correlate with magnetic resonance imaging (MRI) measures (32).

• Articular cartilage: Thinning of articular cartilage, asymmetry, loss of edge, or heterogeneity (29).
• Capsule and synovium: Hypertrophy of the synovial layer and positive color Doppler showing hyperemia within the intraarticular synovium. An effusion and/or cyst connected to a joint, such as a Baker cyst, may be seen (30).
• Bone: Bony hypertrophic growth, i.e., osteophyte, cortical irregularities, cortical erosion.
• Ligament and meniscus: The meniscus may be extruded due to joint space narrowing, displacing ligaments attached to the meniscus (28).
• Periarticular structures: The thickness and quality of the muscle surrounding the joint may be reduced.

Hemophilic joint disease

A severe form of joint disease, hemophilic arthropathy, can develop in early childhood following repetitive joint bleeding episodes (33). Physical therapists play a central role in managing hemophilia by combining diagnostic with rehabilitation responsibilities, performing approximately 70% of point-of-care musculoskeletal exams which directly inform treatment decisions (34). Hemophilia A and B are sex-linked congenital bleeding disorders caused by reduced or absent levels of coagulation factor VIII or IX and are classified as mild, moderate, or severe based on factor levels (35). In the United States, hemophilia affects about 33,000 males (36) and 1,667 females, most of whom have mild disease (37). Prior to prophylactic care, roughly 90% of patients with moderate or severe hemophilia developed arthropathy (38). The most significant manifestation is spontaneous bleeding into joints, particularly the ankles, knees, and elbows (39). Repeated bleeding leads to synovial proliferation, cartilage erosion, and bone destruction, ultimately causing long-term disability (40).

The current standard of care is prophylactic coagulation factor replacement therapy to minimize musculoskeletal complications (35). Early detection of joint bleeding and pathological changes is essential for optimizing treatment and preventing permanent damage (41). In this context, physical therapists use POCUS to identify active bleeding, distinguish between new and chronic joint damage, and guide clinical decision-making (42). Compared to MRI, POCUS accurately evaluates synovial hypertrophy, cartilage, and bone irregularities in these patients (43). Physical therapists report that integrating POCUS into practice frequently results in meaningful changes to treatment plans and improves patient management (44). In this specialty area, ultrasound can help physical therapists determine whether symptoms are more consistent with active bleeding, chronic arthropathy, or another musculoskeletal source, thereby supporting safer timing and progression of rehabilitation.

Ultrasound imaging in ligament injury and pathology

Ultrasound evaluation of ligamentous injuries depends on the location of the involved ligament, with superficial ligaments more easily visualized and, therefore, more easily graded on ultrasound. In high-grade ligament injuries, there may be associated intra-articular injuries that may warrant additional such as an MRI. Limitations of ultrasound imaging compared to MRI include its inability to image through bone, which prevents scanning of osteochondral injuries and makes it difficult to scan deeper ligaments, such as the cruciate ligaments of the knee. However, an advantage of ultrasound over MRI is its ability to image ligaments dynamically, which aids in the grading of ligament injuries.

Musculoskeletal ultrasound findings in grade 1–3 ligament injury include: Ultrasound enables physical therapists to view the ligament and joint movement while assessing ligament integrity. Adding dynamic ultrasound examination to ulnar collateral ligament injuries in the elbow enhances the diagnostic value of MRI and aids in predicting rehabilitation outcomes, with reported sensitivities, specificities, and accuracies of 72.2%, 82.6%, and 78%, respectively (45). Sample diagnostic values of ultrasound for ligament and meniscal injuries are presented in Table 2. Dynamic assessment can complement physical therapy examination by linking tissue integrity with movement behavior, joint stability, symptom reproduction, and functional loading decisions.

• Grade 1—The ligament may show a hypoechoic signal but is grossly intact, with fluid surrounding the ligament in acute cases.
• Grade 2—Partial tear, may appear as hypoechoic thickening of the ligament with fiber interruption, and is sometimes accompanied by osseous avulsion.
• Grade 3—Complete tear of ligament with associated intra-articular injury.

Table 2. Ligament and meniscal injury.

CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; NR, not reported.

Ultrasound imaging in tendon pathology and degenerative changes

Tendon disorders are on the rise, with the current active aging population, affecting quality of life, and placing considerable financial strain on the healthcare systems. Accurate diagnosis is pivotal in managing tendon injuries differentiating between acute trauma, degenerative conditions, or systemic disease (46). According to the American College of Radiology Imaging Appropriateness (ACR) Guidelines, musculoskeletal ultrasound is one of the preferred methods for evaluating tendon pathology (18). Ultrasound can help diagnose tendinopathy, including tendinosis, enthesopathy, tenosynovitis (also known as peritendinitis), and partial and complete tears. Tendon tears can be visualized on ultrasound during both static and dynamic assessments (stress tests). According to the literature, MRI and ultrasound have similar diagnostic capabilities (Table 3). The pathogenesis of tendinopathy is on a continuum from normal to degenerative to tears, and ultrasound can help the physical therapist stage the phases of change, monitor healing, and tailor loading dosage during exercise progressions (47). The location of pathology within the tendon and the body directly relates to the treatment choices based on the different pathomorphologies (48). For musculoskeletal physical therapists, this information can support more individualized load management, patient education, return-to-activity planning, and monitoring of tissue response over time.

Table 3. Tendon pathology.

CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; OR, odds ratio; NR, not reported.

Ultrasound findings may include focal tendon thickening and a hypoechoic, inhomogeneous appearance with a disrupted fiber pattern, resulting from tendon retraction. Power Doppler findings may indicate hyperemia suggestive of active inflammation (49). Secondary cortical changes may be present at the tendon insertion, such as calcific tendinosis (shadowing). Calcific tendinosis exhibits shadowing associated with tendon failure and is frequently accompanied by fluid or calcification in the subacromial-deltoid bursa. Peritendinitis is an inflammation of the peritendon, often accompanied by inflammation of the deep surrounding structures, including the bursa and fat pad. Enthesopathy is insertional tendinopathy visualized by macrocalcifications or calcific foci (hydroxyapatite deposition in the degenerative tendon), often occult on MRI. Tendon dislocation, subluxation, and snapping may be visualized. Diagnostic values of ultrasound for tendon pathologies are presented in Table 3.

Limitations of musculoskeletal ultrasound

Despite the expanding clinical utility of musculoskeletal ultrasound across a range of pathologies, its limitations must be clearly acknowledged to support responsible clinical integration. First, MSK ultrasound is inherently operator-dependent, and diagnostic accuracy is directly tied to the training, experience, and technique of the individual performing the examination. Evidence gaps remain particularly notable in lower extremity stress fractures, where pooled sensitivity ranges widely (0.43–0.99) and ultrasound currently holds limited value as a screening tool for repetitive stress-related bone injury (26); in synovitis of the wrist and knee, where diagnostic odds ratios are modest and studies examining non-wrist or non-knee joints remain sparse (Table 1); and in biceps long head tendon pathology and partial rotator cuff tears, where sensitivity is comparatively lower than for full-thickness tears (Table 3). Second, MRI retains clear superiority in several clinical scenarios where ultrasound has fundamental physical limitations: it cannot image beyond the bony cortex, making it unable to evaluate osteochondral lesions, intra-articular structures such as the cruciate ligaments, or intrinsic bone marrow pathology (50). In high-grade ligament injuries with suspected intra-articular involvement, MRI is the appropriate next step, and ultrasound of deeper ligaments such as the ACL — while feasible — carries substantially higher operator burden (50). Ultrasound findings in joint degeneration, synovitis, and cartilage assessment also remain constrained by the inability to visualize the entire joint surface and intrinsic bony abnormalities — domains where MRI and CT continue to provide superior characterization. Responsible adoption requires that physical therapists use MSK ultrasound as an adjunct to not a replacement for clinical examination and established diagnostic pathways, within defined competency frameworks and with clear referral protocols for findings that exceed the scope of point-of-care assessment.

Ultrasound imaging of peripheral nerve injuries

Peripheral nerve injuries are estimated to represent 2.6% of all upper extremity traumas and 1.2% of all lower extremity traumas admitted to United States emergency departments (51). The incidence of peripheral nerve injuries due to trauma is higher than previous reports. Notably, only 9% of nerve injuries are identified by emergency departments, and only 38% are detected during the final hospital discharge (51). The findings suggest the urgency of improving detection methods during the initial or outpatient visits. Peripheral nerve injuries are suspected in patients who have extremity trauma, have undergone surgeries, or exhibit clinical entrapment neuropathies. The ultrasound probe is positioned to detect focal nerve lesions due to its high diagnostic value (Table 4). For physical therapists, nerve ultrasound may support more precise clinical examination by helping visualize the anatomical source of symptoms, particularly when impairments in sensation, strength, or pain suggest peripheral nerve involvement.

Table 4. Nerve pathology.

CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; NR, not reported.

Electrodiagnostic tests, including nerve conduction studies and electromyography, enable the localization of lesions and assessment of nerve function. They are the gold standard for diagnosing peripheral nerve injuries. Nerve ultrasound complements electrodiagnostic testing by providing structural and morphological information about the nerve (52). Ultrasound imaging plays a key role when tests are combined, especially when electrodiagnostic findings are inconclusive (53, 54). Normal cross-sectional data for nerve ultrasound are established (55–57). An alternative imaging modality for peripheral nerve injury is magnetic resonance neurography. Limited high-resolution quality and lack of normative MRI data for peripheral nerve injuries contribute to the underutilization of MR neurography (58). Further advantages of nerve ultrasound include the feasibility of quick contralateral side comparison and lower costs, as well as the absence of ferromagnetic debris artifacts and implant contraindications. It is hypothetically estimated that if musculoskeletal ultrasound technology was used instead of magnetic resonance imaging when appropriate, from 2006 to 2020, it would have saved the healthcare system 6.9 billion in costs (59).

The nerve ultrasound scan evaluates the continuity of the nerve at any given distance, the presence of focal neuromas, the presence of foreign bodies (in open wound cases), the condition of surrounding tissues and structures, the degree of neighboring scars, changes of nerve cross-section areas proximal and distal to the area of injury and the size and position of any gaps in the nerve course (60). In physical therapy practice, these findings may help identify precautions, guide clinical decision-making, and inform whether conservative intervention, additional diagnostic testing, or referral are indicated. For example, an ultrasound assessment for diagnosing carpal tunnel syndrome includes measurements of the cross-sectional area, wrist-to-forearm ratio, nerve excursion, and evaluation of muscle atrophy (61).

Ultrasound imaging is a powerful tool in diagnosing entrapment neuropathies, and in many instances, it also provides surgical guidance to the appropriate locations of injuries (62). Ultrasound techniques can alter the trajectory of diagnosis and management in peripheral entrapment neuropathies based on imaging findings (63). The nerve ultrasound evaluation extends the physical examination performed by qualified clinicians and providers, including physical therapists, enabling more accurate diagnosis, enhancing confidence in timely referral when needed, and guiding conservative management strategies.

Limitations of peripheral nerve ultrasound

Ultrasound imaging of entrapment neuropathies lacks the ability to provide information about the severity of nerve injury (64). Electrodiagnostic studies are preferred in assessing nerve injury severity according to measured parameters. The MRI and ultrasound imaging provide visual assessment of the nerve morphology, continuity, and pathological tumors. The American College of Radiology identifies both ultrasound and MRI without IV contrast as “maybe appropriate” in the imaging appropriateness category for median neuropathy at the carpal tunnel (18). However, ultrasound is more cost-effective and easier to access and use. MRI and ultrasound assess and detect nerve tumors equally, although tumor excision and biopsy are superior in confirming the nature of the tumor (65). MRI is better in identifying plexus injury compared to ultrasound imaging (66). Ultrasound lacks the ability to visualize deeper structures, and hence MRI is better in assessing deeper nerves, i.e., the proximal sciatic nerve (67).

Cardiovascular ultrasound imaging

Cardiac

Cardiovascular disease (CVD) affects approximately 626 million people globally (68). In the United States, approximately 120 million people currently have one or more forms of cardiovascular disease, including 28.7 million with ischemic heart disease and 12.9 million with heart failure (69–71). The American Heart Association projections indicate CVD prevalence will increase from 11.3% in 2020 to 15.0% by 2050 (72). From cardiovascular ultrasound, known formally as the term “echocardiography” or “echo” serves as the preferred initial imaging modality for evaluation, providing essential structural and functional information about the heart. Given the advanced skills required, this application has primarily been used by echocardiography specialists who have followed a practice competency pathway and demonstrated the necessary acquisition skills. Formal echocardiograms are: 1) acquired by a credentialed sonographer using a defined protocol, 2) interpreted by a trained physician, 3) provided a structured report, 4) archived, and 5) usually conducted through a formal testing facility. In contrast to formal echocardiography, cardiac point-of-care ultrasound (POCUS) does not require any of the five components detailed above. While cardiac POCUS does not replace formal echocardiography, in the hands of a trained provider, it can help the physical therapist identify critical cardiovascular pathologies that may otherwise be missed on physical examination (73–76). For physical therapists, cardiovascular POCUS may enhance clinical decision-making by adding real-time physiologic information to the cardiovascular examination before, during, or after rehabilitation interventions. It is important to recognize that POCUS examinations are focused and lack the quantitative and Doppler assessments required to fully characterize valvular disease, diastolic dysfunction, pulmonary hypertension, and other complex cardiac abnormalities. Therefore, cardiac POCUS findings should be used to identify patients who may benefit from further evaluation rather than serve as a definitive diagnostic assessment (77). Given the wide variety of physical therapy practice settings, it is conceivable that the use of cardiac POCUS could rise dramatically to aid in the screening and treatment of patients. By recognizing signs of cardiac dysfunction, physical therapists can modify treatment plans, postpone sessions, or refer the patient, ultimately enhancing patient safety.

Vascular

One of the earliest reports of arterial and venous Doppler ultrasound assessments in physical therapy (PT) was published in 1983, comparing Doppler evaluations by physical therapists with invasive venograms and arteriograms. The report found that physical therapists demonstrated competence when performing Doppler ultrasound evaluations (78). Vascular POCUS integrates well into physical therapy practice as a screening tool (aorta and deep veins) and to evaluate changes in blood flow during and after PT interventions. There are reports of physical therapists using vascular US to assess arterial blood flow during exercise as a surrogate measure of exercise-induced endothelial shear stress (79). In cardiovascular physical therapy, vascular ultrasound can help physical therapists screen for vascular precautions, monitor physiologic responses to exercise or mobilization, and support timely referral when findings are inconsistent with expected rehabilitation responses.

In emergency medicine, several protocols now exist to evaluate vascular pathology systematically, some of which also include cardiac POCUS. One such protocol is the Rapid Ultrasound in Shock (RUSH) exam, a 3-part bedside physiologic assessment of 1) the pump (heart), 2) the tank [inferior vena cava (IVC) and jugular veins], and 3) the pipes (aorta and deep veins). With one protocol, the examiner assesses cardiac structure and function, intravascular volume status, the presence of an aortic aneurysm or dissection, and deep vein thrombosis (DVT) (80). With high diagnostic values, the RUSH protocol enables the differentiation of shock types (81) (Table 5).

Table 5. Cardiovascular pathology.

CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; NR, not reported.

Integrating cardiovascular POCUS in the physical examination

Despite the ongoing ambiguities of POCUS privileging and reimbursement, there is little debate over the value POCUS provides when incorporated into the physical examination (82). A cardiovascular physical examination should be routinely performed irrespective of the chief complaint and presenting diagnosis, as the PT is certain to place the cardiovascular system under physiologic stress during rehabilitation or mobilization.

There are several qualitative and quantitative methods to assess left ventricular (LV) and right ventricular (RV) systolic function using POCUS. First, parasternal long and short-axis views of the heart allow for visual/subjective estimations of LV contractility (qualitative) as well as E-point septal separation (EPSS) and fractional shortening (quantitative). Studies evaluating the accuracy and utility of cardiac POCUS in primary care and the emergency department performed by non-cardiologists have verified a > 90% accuracy of detecting left ventricular systolic dysfunction (LVSD) primarily when using subjective estimates of systolic function and/or EPSS with cardiac POCUS (78). When evaluating the incremental effect of adding POCUS to traditional bedside evaluation specifically for LVSD by non-cardiologists, sensitivity improves significantly with ultrasound use (82). An apical 4-chamber view of the heart can aid in the discovery of RV dysfunction with either visual assessment of RV/LV (size ratio or by measuring tricuspid valve annular plane systolic excursion (TAPSE) as a quantitative estimate which boasts a high level of accuracy (area under the receiver operating characteristic curve = 0.93, 95% CI, 0.88–0.99) after minimal training, even for non-cardiologists (83). Finally, a subcostal (SC) longitudinal view of the inferior vena cava (IVC) with measurement of the IVC diameter and collapsibility during respiration can reliably estimate central venous pressure (CVP), as well as predict fluid responsiveness (82). Studies comparing the accuracy of jugular venous pressure (JVP) vs. IVC ultrasound found a sensitivity of 14% for JVP, compared to 82% for CVP >10 mmHg. Additionally, IVC ultrasound, even by non-cardiologists, was helpful to predict readmission and in-hospital mortality (82).

Acute DVT is a serious vascular condition requiring accurate diagnosis and treatment to prevent embolization. POCUS screening exams for DVT have risen in popularity, especially in primary care and emergency medicine. Ultrasound (without Doppler) is used to visually inspect veins for echogenic thrombus, and then the transducer is used to compress the target veins at two or three sites in the lower extremity. The diagnosis of DVT is made either by the visualization of an echogenic thrombus or if an area of a vein is not fully compressible. Both 2-point and 3-point exams demonstrate high agreement with ultrasound done by a radiologist or venography (Table 5) (84).

An abdominal aortic aneurysm (AAA) is defined as having an abdominal aorta diameter greater than 3 cm. Most AAAs are asymptomatic until they rupture. Aneurysm size is the strongest predictor of rupture risk, with a significant increase in risk at AAA diameters greater than 5.5 cm, from a 25%–40% five-year cumulative rupture rate (85). If an AAA ruptures, it is a surgical emergency and is associated with a high mortality rate (50%–90%) (86). When compared to intraoperative diagnosis, POCUS had a pooled sensitivity and specificity of 98% and 97%, respectively, for diagnosing AAA, significantly outperforming physical examination alone (Table 5) (86). Vascular problems of the extremities or trunk may present like musculoskeletal extremity or back pain. Physical therapists proficient in cardiovascular POCUS can serve in frontline screening, reducing risk to the patient. These applications complement physical therapy practice by improving recognition of cardiovascular contributors to symptoms that may limit safe participation in exercise and functional training.

Limitations of cardiovascular ultrasound

Cardiovascular POCUS has several important limitations. Unlike comprehensive echocardiography, cardiac MRI, or cardiac CT, POCUS lacks spectral and tissue doppler for quantifying diastolic dysfunction, pulmonary hypertension, or valvular stenosis severity; the tissue characterization capabilities of MRI needed to identify myocardial fibrosis, edema, or infiltrative cardiomyopathies; and the spatial resolution of CT required to evaluate coronary artery disease or pericardial calcification, and is therefore best understood as an adjunct to the physical examination rather than a replacement for formal cardiac imaging (77, 87–90). Additionally, image quality and subsequent diagnostic accuracy are fundamentally dependent on appropriate image acquisition techniques. Patient factors such as limited acoustic windows and body habitus further degrade the data obtainable (88, 91). Operator skill is a major concern, as training standards remain heterogeneous, and studies have shown that POCUS training can paradoxically increase false-positive diagnoses while boosting operator confidence in inaccurate findings (92, 93). This is particularly relevant for non-physician users such as physical therapists, for whom cardiovascular ultrasound has not yet been included in scope of practice reviews (94, 95) and few regulatory bodies provide explicit guidance for physical therapists on ultrasound imaging (9, 95, 96).

Lung ultrasound imaging

Globally, respiratory health is significantly impacted by both acute infections and persistent chronic diseases. Acute respiratory infections caused 2.5 million deaths in 2019, while chronic respiratory diseases affected over 454 million people (97). Although global age-standardized rates have generally declined since 1990, significant public health burdens persist today (97). In the United States, acute infections were the fourth leading cause of death in 2020, while the country currently reports one of the world’s highest chronic disease prevalence rates overall (98).

Lung ultrasound, which encompasses examination of pleura and parenchymal structures or pathologies, is a relatively new addition to the field of ultrasound imaging. Professor Daniel Lichtenstein advocated using ultrasound to assess and diagnose lung pathologies, such as pneumothorax, interstitial syndrome, consolidation, and pleural effusion in the 1990s and 2000s, culminating in his publication on respiratory failure, which included the BLUE (Bedside Lung Ultrasound in Emergency) protocol (99). The BLUE protocol has established the foundation for the use of lung ultrasound among various healthcare professions, including physical therapy. The first published report documenting a physical therapist’s use of lung ultrasound was a conference abstract by Riley et al. (100) in 2014. Since then, over 60 papers have been published on lung ultrasound involving physical therapy (101).

The accuracy (sensitivity and specificity) of lung ultrasound to identify pleural and parenchymal pathologies has been shown to have high diagnostic values in multiple systematic reviews, including pneumothorax (102), interstitial syndrome (103), consolidation (104), and pleural effusion (104), Sample diagnostic values are reported in Table 6. The evidence showing the benefit of lung ultrasound in both physical therapy practice and service user experience/outcomes is in its infancy but growing rapidly. In the hands of a physical therapist, lung ultrasound can image the lung and associated anatomy for diagnostics, screening, treatment monitoring, and biofeedback (105) across a wide range of acute hospital, outpatient, community, and domiciliary settings (106). The evaluation of unexplained patient/client signs or symptoms, particularly when alternative assessment methods or imaging are unclear or absent, enables physical therapists to screen for both precautions and contraindications to their chosen treatments and interventions, making patient care safer.

Table 6. Lung and diaphragm pathology.

CT, computed tomography; CI, confidence interval; LR+, positive likelihood ratio; LR-, negative likelihood ratio; OR, odds ratio; NR, not reported.

Diaphragm ultrasound

It wasn't until the late 1990s that the use of diaphragm ultrasound was reported in physical therapy research. However, a diaphragm ultrasound was performed by a sonographer rather than a physical therapist (107). The first reported use of diaphragm ultrasound performed by a physical therapist was in 2013, by an Australian group investigating diaphragm muscle changes in critically ill patients (108). Since then, over 70 papers have been published on diaphragm ultrasound, with physical therapists performing the examinations themselves as part of their research and clinical practice (109).

As a vital respiratory muscle, the diaphragm can be assessed with ultrasound to provide non-invasive and serial measures of dysfunction. Under expert mentorship, the technique can be learned relatively quickly, allowing it to be performed at almost any location (bedside, clinic, etc.) where the correct equipment is available. Diaphragm ultrasound allows the identification of normal function, reduced mobility, weakness, loss of function, or paralysis (110).

Established Diaphragm Ultrasound Measures:

Excursion/mobility

Using the liver as an acoustic window, the right hemidiaphragm can be imaged relatively easily by placing the ultrasound transducer below the right costal margin. After correct visualization of the right hemidiaphragm by B-mode, M-mode is used to display the motion of the diaphragm. In contrast, using the spleen as an acoustic window for the left hemidiaphragm is more challenging due to the spleen’s small size and the presence of aerated abdominal structures, such as the stomach and intestines, which block the view (110).

Diaphragm muscle thickness

This intercostal approach is performed using a linear transducer in the zone of apposition (ZOA) between the mid-axillary or antero-axillary line, in the 8th to 11th intercostal space. The diaphragm appears as a three-layered structure between the pleural and peritoneal membranes. The ultrasound machine calipers are used to measure the thickness of the diaphragm between the two membranes (110).

Diaphragm thickening fraction

The diaphragm thickens with active shortening; therefore, the thickening fraction reflects contractile activity. The thickening fraction of the diaphragm is calculated using the same measurement method as diaphragm thickness, but at different time-points during the respiratory cycle. Diaphragm thickness is expressed as a percentage (%) and calculated by using the equation in Box 1 (110).

Thickening fraction (TFdi %)

TFdi% = (End Inspiratory thickness – End Expiratory thickness)/End Expiratory thickness × 100.

Limitations of lung and diaphragm ultrasound

Despite the growing evidence supporting lung ultrasound (Table 6), several limitations should be considered for successful integration into physical therapy practice. Lung ultrasound is useful for diagnosing pleural and peripheral lung abnormalities; however, deeper lesions surrounded by aerated lung tissue may be missed. Because lung ultrasound can examine only approximately 70% of the pleural surface, disease severity may be underestimated (111). In addition, nonspecific artifacts and imaging patterns are common, requiring skilled operators to distinguish clinically relevant findings from irrelevant ones (112, 113). Lung ultrasound may also be more difficult in patients with obesity because increased soft tissue thickness increases the distance sound waves must travel. Compared with chest radiography, CT is more sensitive and, in some cases, may also be more sensitive than ultrasound (111). MRI is most useful for assessing mediastinal masses and soft tissues, although it may not be well tolerated by patients who are claustrophobic or agitated.

Although diaphragm ultrasound demonstrates moderate-to-high specificity for predicting extubation failure risk (Table 6), operator skill remains a significant concern (114). Standardized quantitative thresholds are also lacking (115). Additional limitations include the inability to visualize the entire diaphragm (114), and the left hemidiaphragm is often more difficult to assess than the right (116). Other imaging techniques used to assess diaphragmatic dysfunction, such as plain radiography and CT, rely on static images to indirectly assess muscle motion and expose patients to ionizing radiation (114). Dynamic MRI can provide reliable measurements of excursion across the entire diaphragm; however, it is more costly and not widely available (117).

Pelvic ultrasound imaging

Pelvic floor dysfunction is a common and burdensome condition with widespread global impact, affecting millions of people and posing substantial public health challenges (118–121). Approximately 25%–33% of women present with at least one type, with the likelihood increasing with age and childbirth (120, 121). The main types of pelvic floor dysfunction include urinary incontinence, pelvic organ prolapse, and fecal incontinence. The most common type of pelvic floor dysfunction, urinary incontinence, affects 25%–45% of women and a smaller proportion of men (10%–20%) (122), with prevalence increasing with age. Other conditions affecting the lower urinary tract, such as urinary urgency and frequency, may affect up to 60% of adults worldwide, with pelvic organ prolapse affecting 3%–50% of women and fecal incontinence affecting 7%–10% of individuals (123, 124). Key risk factors include age, increased parity, obesity, and, in men, prostate-related conditions, thus highlighting pelvic floor dysfunction as a widespread and often under-reported issue (118).

The pelvic floor and other pelvic structures are frequently overlooked despite their significant functional importance in maintaining continence, supporting pelvic organs, and contributing to lumbopelvic postural control (125). Rehabilitative ultrasound imaging was initially defined as a “procedure used by physical therapists to evaluate muscle and related soft tissue morphology and function during exercise and physical tasks…and to assist in applying therapeutic interventions aimed at improving neuromuscular function” (126). Ultrasound imaging of the lumbopelvic region has been extensively studied and is recognized as a valid and reliable tool for diagnosis and treatment in physical therapy (127). For pelvic health physical therapists, ultrasound imaging extends the clinical examination by allowing noninvasive visualization of pelvic floor muscle behavior during rest, contraction, and functional tasks.

In the early 2000s, pelvic health physical therapists in the United States began using ultrasound imaging as a biofeedback tool because it can visualize pelvic floor muscle function. This included assessment of bladder base elevation and bladder neck displacement during attempted pelvic floor muscle contractions, while recognizing that some individuals may instead demonstrate caudal displacement associated with a bearing down/straining maneuver rather than a contraction (125). Different ultrasound technologies and views can provide a variety of indicators imaged in 2D, 3D or with shear wave elastography. Shear wave elastography uses an acoustic radiation pulse within the ultrasound beam to assess tissue’s mechanical and elastic properties (128). While 2D is most commonly used in pelvic health physical therapy, 3D and shear wave elastography are widely used in research. This real-time visualization can help physical therapists confirm whether the intended muscle response is occurring and adjust verbal, tactile, or exercise cues immediately during the session.

Evaluation and biofeedback

Traditionally, physical therapists relied on digital exams, electromyography, or perineometry using vaginal/anal sensors as a method of evaluating pelvic floor dysfunction (129). While these methods are still used today, they have limitations. The validity of sensor-based measurements is limited by potential crosstalk from adjacent musculature (130). Bearing down during perineometry also confounds electromyographic signals and may aggravate symptoms in individuals with urinary incontinence and pelvic organ prolapse (131). Consequently, the International Urogynecological Association (IUGA) and the International Continence Society (ICS) reported that these devices should not be used alone but should be used in conjunction with ultrasound imaging or a digital pelvic exam to confirm appropriate pelvic floor muscle contraction (132).

The integration of ultrasound imaging into pelvic health physical therapy practice enables real-time observation of PFM function and structures dynamically via the effects on the bladder base or neck, the anorectal angle, the levator plate, and the levator hiatus (133–136). Pelvic floor morphology, deformation, and displacement of pelvic structures can also be visualized before, during, and after contraction. In addition to using transabdominal or transperineal B-mode, shear wave elastography measures the stiffness of pelvic floor structures.

As a biofeedback tool, rehabilitative ultrasound imaging is more effective than tactile and/or verbal feedback (137, 138). A recent systematic review reported that more than 95% of women can correctly contract their pelvic floor muscles following ultrasound visual feedback training (139). Furthermore, ultrasound visual feedback is more specific than intravaginal palpation for assessing pelvic floor muscle function and provides visible information about its supportive function during various dynamic tasks (125).

Ultrasound imaging can redefine pelvic health physical therapy by providing objective, real-time visualization of pelvic floor muscle function, enabling physical therapists to distinguish true pelvic floor muscle activation from compensatory strategies to deliver more precise evidence-based care. When integrated with history, symptom behavior, functional assessment, and patient goals, ultrasound can help guide exercise progression, reinforce motor learning, and monitor response to pelvic health rehabilitation over time.

Limitations of pelvic ultrasound

Although ultrasound imaging yields valuable information about pelvic floor muscle structure and function, it has limitations. Additional clinical assessment and, in some cases, additional imaging may be required when examining complex pelvic floor disorders (140, 141). For example, dynamic MRI and MR defecography may be useful when a more detailed assessment of pelvic organ support, multicompartment prolapse, connective tissue involvement, or other structural abnormalities are required. Consequently, the clinical question should determine the choice of imaging, with ultrasound delivering a practical method for assessing dynamic pelvic floor function in rehabilitation and MRI providing additional anatomical information when indicated (142–144).

Patient safety concerns

The importance of patient safety, scope of competency, and clear referral pathways is central to the application of point-of-care ultrasound (POCUS) into physical therapist practice. Physical therapists have an established role in medical screening and referral when patient history, systems review, physical examination findings, response to intervention, or imaging findings suggest a condition outside the scope of physical therapist management (145). Evidence from direct-access physical therapy settings also suggests that physical therapists can use diagnostic imaging judiciously and can expedite definitive care when imaging identifies conditions such as extremity fracture (146, 147). However, POCUS should not be interpreted as permission to practice outside one’s legal scope, training, or demonstrated competency. Ultrasound imaging is highly operator-dependent, and inappropriate use by insufficiently trained clinicians may lead to misinterpretation, misdiagnosis, false reassurance, or delayed medical care (95, 148). This concern is particularly important when POCUS is used to screen for serious or sinister conditions that may present with symptoms commonly encountered in physical therapy practice, including suspected deep vein thrombosis, abdominal aortic aneurysm, fracture, cardiopulmonary pathology, hemarthrosis, or other non-neuromusculoskeletal sources of pain (145, 149–153). Although condition-specific POCUS literature supports the diagnostic utility of ultrasound for selected vascular and musculoskeletal conditions, negative or normal findings should not supersede clinical suspicion or delay referral for comprehensive diagnostic imaging, emergency care, or specialty consultation when indicated (148, 151–153). Therefore, physical therapists should use POCUS as an adjunct to the clinical examination rather than a replacement for referral, perform and interpret ultrasound only within legal scope and demonstrated competency, and establish referral pathways for findings that are outside the clinician’s scope or concerning for time-sensitive pathology.

Education leading to competence

Educational models

Universities, professional groups, equipment vendors, and private education providers offer a complex mix of educational options. Ultrasound imaging education can vary from a single lecture to multiple lectures in a course. It can include lab sessions or a weekend course. Ultrasound educational content can be threaded longitudinally throughout the curriculum or as a postgraduate fellowship. Standardization of curriculum content has been a challenge in medical education; however, progress was made in 2022 when 332 comprehensive statements were developed based on the International Consensus Conference recommendations (154), which included 28 specific education consensus statements that discussed the scope, rationale, and characteristics of ultrasound education, serving as a guide for curricular development.

Ultrasound education is diverse, not only in Doctor of Physical Therapy (DPT) curricula but also in postgraduate and professional training courses. Ultrasound use has gained rapid adoption in healthcare and physical therapy. However, as a profession, we need to ensure that education and training keep pace with the speed and implementation of this tool. Whittaker et al. concluded that competency standards were essential to ensure “training and practice standards were identified, reached and maintained” (95). It is essential that future physical therapists understand when to use ultrasound, how to utilize it effectively, and ensure they have the necessary education and skills to avoid misuse, which could impact patient care (155).

Ultrasound education began in medical schools in the 1990s. Since then, many medical schools in the United States have implemented ultrasound training into their curricula. As of 2019, 72.6% of medical schools report that ultrasound imaging is included in the curriculum (156). Ultrasound imaging has been integrated into basic science courses, clinical skills courses, clinical rotations, residencies, and fellowships (156, 157). Hoppmann et al. (154) suggested that the integration of point-of-care ultrasound imaging should be early in medical education programs and, more importantly, ensure that learning outcomes are observable and measurable. Physical therapy programs should take note of the advice from medical education statements, ensuring that they are established with high standards and linked to educational outcomes. Several studies reported limited training, experience, or skill level as potential limitations to achieving competent implementation and image acquisition using ultrasound imaging (158–160). Recognizing these limitations could enable educational institutions to efficiently modify their DPT curricula to ensure high-quality implementation and image acquisition. Artificial intelligence (AI) has the potential to improve the learning curve, facilitate image acquisition, provide accurate measurements, and enable novice learners to develop the skills necessary to apply ultrasound imaging more efficiently and effectively (161, 162). According to Höhne et al, digital learning approaches incorporating AI and mobile applications were just as successful as conventional practical instructions when teaching ultrasound skills to medical students (163). The integration of AI and ultrasound imaging in both educational and clinical settings remains in its early stages, while this brings considerable potential, it will require greater standardization of image acquisition protocols as well as clearer guidance on implementation practices. Continued research is required to fully establish its role in clinical practice and education.

Educating physical therapists and students on the indications for ultrasound imaging would be valuable, particularly as physical therapists’ role as primary care providers continues to grow (7, 164–168). A 2023 national survey of DPT programs found that 70% incorporated ultrasound education into their curricula (157). Fifty percent of the programs reported that ultrasound imaging is an entry-level skill. Responders reported that programs should incorporate education on ultrasound for diagnostic purposes (36.4%), assist learning (29.9%), and biofeedback (29.9%) (157). In 2018, a study triangulated survey data with educational guidelines and a literature search to conclude that there is strong evidence for the need for ultrasound imaging in DPT education (169). Due to the multidisciplinary of physical therapy curricula, ultrasound imaging should not be taught in a single course, but rather, woven and integrated into a DPT curriculum. This research supports the longitudinal incorporation of ultrasound education into the DPT curriculum and its transition to clinical practice principles (169).

Introducing ultrasound imaging into foundational courses, such as anatomy, allows students to visualize living anatomy, the three-dimensional spatial relationships between structures, and the live movement of muscles and joints during dynamic scanning. This provides visual information that is not easily obtained using traditional pedagogical techniques, such as digital anatomy and cadaveric dissection. Edwards et al. surveyed 107 undergraduate students who participated in five ultrasound sessions as part of an anatomy course. Ninety-three percent perceived an improvement in their understanding of anatomy following the instruction (170). Similarly, the use of ultrasound by first-year medical students in gross anatomy effectively enhanced student confidence and comprehension of anatomy (171).

Hazel et al. compared the results from their 2013 survey with those from the 2023 survey (172). They identified a notable trend in recognizing the value of diagnostic US in augmenting the physical therapist’s clinical examination. The number of programs that assessed student competencies in identifying soft tissue pathological processes/injuries using ultrasound imaging increased from 40.4% to 57.9%. The competency assessment of identifying normal anatomy with ultrasound also increased from 40.4% to 51.2%.

Physical examination skills are believed to improve with exposure to ultrasound imaging, resulting in a more precise understanding of anatomical relationships. In a systematic review by Oteri et al. (173), eight of nine reviewed studies identified improvement in physical examination practical test scores among medical students who participated in ultrasound lectures. Studies using self-assessment questionnaires consistently reported that ultrasound imaging lectures and activities improved students’ understanding, confidence, and/or skills in performing physical examination procedures (169, 173–175). A small RCT demonstrated that when ultrasound is compared with usual education in courses, ultrasound-based training may improve physical therapy students’ skills, especially regarding the accuracy of palpation (176).

Barriers

Barriers to implementation in DPT curricula have been identified and are similar to those encountered in medical school (157). The cost of devices, the availability of ultrasound equipment, faculty resources, the limited number of trained individuals, the time allocated in the course or curriculum, and the standardization of instructor methods have all been identified as obstacles to integrating ultrasound education into physical therapy curricula (9, 157). As this technology has become more portable, affordable, and user-friendly, an increasing number of physical therapists are utilizing this valuable instrument. The cost of ultrasound imaging equipment has decreased in recent years as the quality of the image and the educational opportunities have improved.

Conclusion

In this narrative paper, we summarized current evidence regarding the clinical utility of ultrasound imaging as a point-of-care tool in physical therapy practice across multiple specialty areas. Ultrasound imaging can provide objective, real-time information that complements traditional physical examination findings, including observation, palpation, movement analysis, strength testing, and special tests. By allowing visualization of bone, ligament, tendon, muscle, nerve, heart, vascular, lung, diaphragm, and pelvic structures, ultrasound imaging may help physical therapists confirm, clarify, or modify clinical impressions and support more informed clinical reasoning.

In selected clinical contexts, ultrasound imaging has demonstrated diagnostic performance that is comparable to, or greater than, commonly used clinical tests in physical therapy practice. Its utility may therefore include identifying or characterizing pathology, monitoring tissue morphology and healing, guiding clinical decision-making, informing the need for additional imaging or referral, supporting image-guided procedures where permitted, and enhancing patient education through visual feedback. These applications may be particularly relevant as physical therapists continue to practice in direct-access and other primary care settings. Physical therapists have established training in anatomy, biomechanics, movement analysis, and physical examination. Ultrasound imaging may extend these existing competencies by providing visual information that can help confirm, clarify, or modify findings from the physical examination. Ultrasound has been described as a point-of-care diagnostic instrument that may be used by healthcare professionals to support clinical decision-making. As physical therapists continue to function in direct-access and collaborative care roles, the integration of ultrasound imaging into clinical practice warrants further consideration.

Although the evidence base is expanding, the broader use of ultrasound imaging in physical therapy should be accompanied by clear professional standards, appropriate education, and competency-based training. Such preparation may support accurate pathology identification, inform decisions regarding the need for additional imaging or referral, and facilitate patient education. This review is intended to contribute to ongoing discussion regarding the appropriate role of ultrasound imaging as a practical clinical tool within physical therapy practice, with the broader goal of supporting patient care.

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Footnotes

Edited by: Francesca Bandinelli, Azienda USL Toscana Centro, Italy

Reviewed by: Stavros Daoukas, London South Bank University, United Kingdom

Tamjeed Ghaffar, Government College University, Faisalabad, Pakistan