In Hamstring Muscles of Patients With Knee Osteoarthritis an Increased Ultrasound Shear Modulus Indicates a Permanently Elevated Muscle Tonus

Changes in gastrocnemius MTU stiffness and their correlation with plantar pressure in patients with knee osteoarthritis

Background

Abnormal, excessive, and repetitive knee load is a critical risk factor for osteoarthritis (OA). The gastrocnemius muscle-tendon unit (MTU) interacts with foot biomechanics and is vital in cushioning the knee load. Abnormal gastrocnemius activation and plantar pressure during walking in patients with knee OA may negatively affect gastrocnemius MTU stiffness, increasing knee load. Few studies investigated the relationship between gastrocnemius MTU stiffness and plantar pressure. This study aimed to evaluate the changes in gastrocnemius MTU stiffness in patients with knee OA and their correlations with plantar pressure and clinical symptoms.

Methods

Thirty women patients with unilateral knee OA and 30 healthy women participants were recruited. Shear wave elastography was used to quantify gastrocnemius MTU stiffness in ankle resting and anatomical 0° positions, defined as natural and neutral positions in this study. A plantar pressure analysis system was used to collect the plantar pressure parameters on the symptomatic side in patients with knee OA. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analogue Scale (VAS) scores were used to measure the severity of clinical symptoms.

Results

Medial and lateral gastrocnemius (MG and LG) stiffness on both the asymptomatic and symptomatic sides in patients with knee OA was increased compared with that in healthy participants. The MG and LG optimal cutoff stiffness in the natural position was 15.73 kPa and 14.25 kPa, respectively. The optimal cutoff stiffness in the neutral position was 36.32 kPa and 25.43 kPa, respectively, with excellent sensitivity and specificity. The MG and LG stiffness were positively correlated with the percentages of anterior and medial plantar pressure and negatively correlated with the length of pressure center path. The LG and MG were significantly correlated with WOMAC and VAS scores.

Conclusion

Patients with knee OA have increased gastrocnemius muscle stiffness, closely related to plantar pressure and clinical symptoms. Monitoring the gastrocnemius muscle in patients with knee OA can provide an essential basis for its prevention and treatment.

Is musculoskeletal pain associated with increased muscle stiffness? Evidence map and critical appraisal of muscle measurements using shear wave elastography

INTRODUCTION AND AIMS

Approximately 21% of the world's population suffers from musculoskeletal conditions, often associated with sensations of stiff muscles. Targeted therapy requires knowing whether typically involved muscles are objectively stiffer compared to asymptomatic individuals. Muscle stiffness is quantified using ultrasound shear wave elastography (SWE). Publications on SWE-based comparisons of muscle stiffness between individuals with and without musculoskeletal pain are increasing rapidly. This work reviewed and mapped the existing evidence regarding objectively measured muscle stiffness in musculoskeletal pain conditions and surveyed current methods of applying SWE to measure muscle stiffness.

METHODS

A systematic search was conducted in PubMed and CINAHL using the keywords "muscle stiffness", "shear wave elastography", "pain", "asymptomatic controls" and synonyms. The search was supplemented by a hand search using Google Scholar. Included articles were critically appraised with the AXIS tool, supplemented by items related to SWE methods. Results were visually mapped and narratively described.

RESULTS

Thirty of 137 identified articles were included. High-quality evidence was missing. The results comprise studies reporting lower stiffness in symptomatic participants, no differences between groups and higher stiffness in symptomatic individuals. Results differed between pain conditions and muscles, and also between studies that examined the same muscle(s) and pathology. The methods of the application of SWE were inconsistent and the reporting was often incomplete.

CONCLUSIONS

Existing evidence regarding the objective stiffness of muscles in musculoskeletal pain conditions is conflicting. Methodological differences may explain most of the inconsistencies between findings. Methodological standards for SWE measurements of muscles are urgently required.

Diagnostic utility of shear wave elastography in musculoskeletal injuries: A narrative review

Shear wave elastography (SWE) is an emerging and promising ultrasound modality, and is more recently employed in the diagnosis of musculoskeletal (MSK) pathologies. SWE evaluates tissue stiffness by measuring the speed of propagating acoustic waves through body tissue structures. Knowing the variations in stiffness of MSK soft tissue can provide helpful diagnostic insight for the evaluation of pathology in muscles, tendons, ligaments, nerves, and other soft tissues. The goal of this review is to synthesize recent literature on the utility of SWE for MSK pathology diagnosis. This review reveals that SWE adds important diagnostic data for the evaluation of several pathologies, such as median mononeuropathy at the wrist, Achilles tendinopathy, and plantar fasciitis. The review also reveals a lack of evidence pertaining to appropriate standardization of use and the connection to reliable and valid diagnostic benefit in the clinical setting.

Comparison of instrument-assisted soft tissue mobilization and proprioceptive neuromuscular stretching on hamstring flexibility in patients with knee osteoarthritis

Background

The association between hamstring tightness and knee osteoarthritis (KOA) is significant because tight hamstrings can put more strain on the knee joint, reduce its range of motion, and cause compensatory movements that worsen the KOA.

Objective

To compare the effects of instrument-assisted soft tissue mobilization (IASTM) and proprioceptive neuromuscular (PNF) on hamstring flexibility in patients with KOA.

Methods

Data for the randomized controlled trial (NCT05110326) was collected from n = 60 participants randomly divided into group A received IASTM and group B received PNF stretching. In group A, the therapist made 30 strokes gentle strokes with the tool from the origin to the insertion while holding the plane at a 45-degree angle over the treatment area. In group B, PNF stretching was done with three repetitions and 10 seconds rest between each, after isometric contraction of the hamstring muscle using approximately 50% of their maximum strength, holding it for 8 seconds, and then releasing it. A 30-minute session was given to each patient three times per week and was given for 6 weeks. Outcome measures were the visual analog scale (VAS) for pain intensity, the active knee extension test (AKET) for hamstring flexibility, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) for the health status of KOA patients.

Results

The study found a significant interaction (p < 0.001) between interventions and time across several measurements. After 6 weeks, both interventions resulted in significant improvements (p < 0.001) across all dependent variables, with group A (IASTM) showing more significant improvement in hamstring flexibility, pain reduction, and health status (p < 0.001) compared to group B (PNF).

Conclusions

Both the IASTM technique and PNF stretching resulted in increased hamstring flexibility, decreased pain, and enhanced general health. The IASTM technique, however, showed potential benefits over PNF stretching in terms of flexibility, pain relief, and public health enhancement. Physical therapists and manual therapists may prioritize the usage of the IASTM technique for patients who want to make significant changes in these areas.

Latest advancements in imaging techniques in OA

The osteoarthritis (OA) research community has been advocating a shift from radiography-based screening criteria and outcome measures in OA clinical trials to a magnetic resonance imaging (MRI)-based definition of eligibility and endpoint. For conventional morphological MRI, various semiquantitative evaluation tools are available. We have lately witnessed a remarkable technological advance in MRI techniques, including compositional/physiologic imaging and automated quantitative analyses of articular and periarticular structures. More recently, additional technologies were introduced, including positron emission tomography (PET)-MRI, weight-bearing computed tomography (CT), photon-counting spectral CT, shear wave elastography, contrast-enhanced ultrasound, multiscale X-ray phase contrast imaging, and spectroscopic photoacoustic imaging of cartilage. On top of these, we now live in an era in which artificial intelligence is increasingly utilized in medicine. Osteoarthritis imaging is no exception. Successful implementation of artificial intelligence (AI) will hopefully improve the workflow of radiologists, as well as the level of precision and reproducibility in the interpretation of images.