Reliability and validity of a semi-electronic tissue compliance meter to assess muscle stiffness

Pain, function and peritendinous effusion improvement after dry needling in patients with long head of biceps brachii tendinopathy: a single-blind randomized clinical trial

INTRODUCTION

Long head of biceps brachii tendinopathy, a frequent source of anterior shoulder pain, may lead to discomfort and diminished function. The objective of this study is to assess the efficacy of dry needling and transcutaneous electrical nerve stimulation in these patients.

PATIENTS AND METHODS

Thirty patients were randomized into dry needling and transcutaneous electrical nerve stimulation groups and assessed before treatment, 8 and 15 days after treatment using a visual analogue scale, shoulder pain and disability index, pressure pain threshold, tissue hardness, and biceps peritendinous effusion.

RESULTS

Both treatments significantly reduced the visual analogue scale in immediate (p < 0.001), short-term (p < 0.01), and medium-term effects (p < 0.01). Dry needling outperformed transcutaneous electrical nerve stimulation for the pain (p < 0.01) and disability (p < 0.03) subscales of the shoulder pain and disability index in the short-term and medium-term effects, respectively. Pressure pain threshold increased after both treatments but didn't last beyond 8 days. Neither treatment showed any improvements in tissue hardness of the long head of biceps brachii muscle. Notably, only the dry needling group significantly reduced biceps peritendinous effusion in both short-term and medium-term effects (p < 0.01).

CONCLUSIONS

Dry needling showed non-inferior results to transcutaneous electrical nerve stimulation in reducing pain and disability and demonstrated even superior results in reducing biceps peritendinous effusion (see Graphical Abstract).

TRIAL REGISTRATION

The Institutional Review Board of the China Medical University Hospital (CMUH107-REC2-101) approved this study, and it was registered with Identifier NCT03639454 on ClinicalTrials.gov.

Reliability and validity of an app-assisted tissue compliance meter in measuring tissue stiffness on a phantom model

Background

Most methods for soft tissue stiffness assessment require high financial resources, significant technical effort, or extensive therapist training. The PACT Sense device was developed to be used in a wide range of applications and user groups. However, to date, there are no data on its validity and reliability. The aim of this study was to investigate the validity and reliability of the PACT device.

Methods

A polyurethane phantom tissue model (PTM) mimicking the mechanical properties of the fascia profunda and the erector spinae muscle was used. Stiffness measurements with PACT were conducted by two independent investigators. For construct validity, correlations were calculated between the known stiffness of the PTM and values obtained with PACT. For concurrent validity, we determined the association between the PACT values and additional measurements with the established MyotonPRO device. To estimate interrater and intrarater (two measurements with an interval of 7 days) reliability, we used the intraclass correlation coefficient (ICC).

Results

Correlation analysis (PTM/PACT) revealed very high concurrent validity (r = 0.99; p < 0.001), construct validity (PACT/MyotonPRO) was 0.87, p < 0.001. Both, interrater reliability (ICC = 0.85; p = 0.036) and intrarater reliability were good (ICC = 0.89; p < 0.001).

Conclusions

The PACT provides valid and reliable stiffness measurements in tissue phantoms. Further studies in humans are needed to confirm its physiometric properties under in vivo conditions.

MRI T2 mapping and shear wave elastography for identifying main pain generator in delayed-onset muscle soreness: muscle or fascia?

INTRODUCTION

The main generator of delayed onset muscle soreness (DOMS) is still unknown. This study aimed to clarify the main generator of DOMS.

METHODS

Twelve participants performed eccentric exercise (EE) on lower legs. MRI and ultrasound were used to assess changes of calf muscle and deep fascia before and after EE. These results were then compared to the muscle pain level.

RESULTS

Compared to baseline, muscle pain peaked at 24-48 h after EE (downstairs 22.25 ± 6.196, 57.917 ± 9.298, F = 291.168, p < 0.01; resting 5.833 ± 1.899, 5.083 ± 2.429, F = 51.678, p < 0.01). Shear wave speed (SWE) of the deep fascia and T2 values of the gastrocnemius muscle and deep fascia all increased and peaked at 48 h after EE (1.960 ± 0.130, F = 22.293; 50.237 ± 2.963, F = 73.172; 66.328 ± 2.968, F = 231.719, respectively, p < 0.01). These measurements were positively correlated with DOMS (downstairs: r = 0.46, 0.76, 0.87, respectively, p < 0.001; resting: r = 0.42, 0.70, 0.77, respectively, p < 0.001). There was a significant positive correlation between SWE and T2 values of deep fascia (r = 0.54, p < 0.01).

CONCLUSION

DOMS is a common result of muscle and fascia injuries. Deep fascia edema and stiffness play a crucial role in DOMS, which can be effectively evaluated MR-T2 and SWE.

CRITICAL RELEVANCE STATEMENT

Delayed-onset muscle soreness is a common result of muscle and deep fascia injuries, in which the edema and stiffness of the deep fascia play a crucial role. Both MRI and shear wave elastography can be effectively used to evaluate soft tissue injuries.

KEY POINTS

• The deep fascia is the major pain generator of delayed-onset muscle soreness. • There is a significant correlation between fascia injury and delayed-onset muscle soreness. • MRI and shear wave elastography are preferred methods for assessing fascia injuries.

Myofascial stiffness of plantar fascia and Achilles tendon in individuals with plantar fasciopathy: An observational cross-sectional study

BACKGROUND

Assessment of myofascial tissue stiffness have a role in identifying physical impairments in plantar fasciopathy (PF). It is still unclear which specific functional and tissue differences exist between individuals with PF.

AIM

To compare myofascial stiffness of plantar fascia, Achilles tendon, and triceps surae between symptomatic and asymptomatic limbs in individuals with PF and between individuals with and without PF.

METHODS

Thirty nine individuals diagnosed with PF and individuals with no history of PF were recruited. Myofascial stiffness of the plantar fascia, Achilles tendon, and triceps surae, range of motion, and clinical tests were performed. Mean difference (MD) and 95% confidence interval (CI) were calculated.

RESULTS

Individuals with PF showed lower mean stiffness in Achilles tendon insertion (MD = -1.00 N/mm; 95%CI: -1.80,-0.21) on the symptomatic limb compared to the corresponding symptomatic limb in control group, a lower mean stiffness in plantar fascia (MD = -0.16 N/mm; 95%CI: -0.30, -0.01) on the symptomatic limb compared to asymptomatic limb, and a lower mean stiffness in the region 3 cm above the Achilles tendon insertion (MD = -0.79; 95%CI: -1.59, -0.00) compared to control. Individuals with PF showed fewer repetitions in heel rise test (MD = -3.97 reps; 95%CI: -5.83, -2.12) and in the step-down test (MD = -5.23 reps; 95%CI: -7.02, -3.44) compared to control.

CONCLUSIONS

Individuals with PF present reduced stiffness in Achilles tendon insertion and plantar fascia. The reduced stiffness was more evident in Achilles tendon in individuals with PF compared to individuals without PF. Individuals with PF showed lower performance in clinical tests.

The Utility of Myotonometry in Musculoskeletal Rehabilitation and Human Performance Programming

Myotonometry is a relatively novel method used to quantify the biomechanical and viscoelastic properties (stiffness, compliance, tone, elasticity, creep, and mechanical relaxation) of palpable musculotendinous structures with portable mechanical devices called myotonometers. Myotonometers obtain these measures by recording the magnitude of radial tissue deformation that occurs in response to the amount of force that is perpendicularly applied to the tissue through a device's probe. Myotonometric parameters such as stiffness and compliance have repeatedly demonstrated strong correlations with force production and muscle activation. Paradoxically, individual muscle stiffness measures have been associated with both superior athletic performance and a higher incidence of injury. This indicates optimal stiffness levels may promote athletic performance, whereas too much or too little may lead to an increased risk of injury. Authors of numerous studies suggested that myotonometry may assist practitioners in the development of performance and rehabilitation programs that improve athletic performance, mitigate injury risk, guide therapeutic interventions, and optimize return-to-activity decision-making. Thus, the purpose of our narrative review was to summarize the potential utility of myotonometry as a clinical tool that assists musculoskeletal clinicians with the diagnosis, rehabilitation, and prevention of athletic injuries.

Assessing reliability and validity of different stiffness measurement tools on a multi-layered phantom tissue model

Changes in the mechanical properties (i.e., stiffness) of soft tissues have been linked to musculoskeletal disorders, pain conditions, and cancer biology, leading to a rising demand for diagnostic methods. Despite the general availability of different stiffness measurement tools, it is unclear as to which are best suited for different tissue types and the related measurement depths. The study aimed to compare different stiffness measurement tools' (SMT) reliability on a multi-layered phantom tissue model (MPTM). A polyurethane MPTM simulated the four layers of the thoracolumbar region: cutis (CUT), subcutaneous connective tissue (SCT), fascia profunda (FPR), and erector spinae (ERS), with varying stiffness parameters. Evaluated stiffness measurement tools included Shore Durometer, Semi-Electronic Tissue Compliance Meter (STCM), IndentoPRO, MyotonPRO, and ultrasound imaging. Measurements were made by two independent, blinded examiners. Shore Durometer, STCM, IndentoPRO, and MyotonPRO reliably detected stiffness changes in three of the four MPTM layers, but not in the thin (1 mm thick) layer simulating FPR. With ultrasound imaging, only stiffness changes in layers thicker than 3 mm could be measured reliably. Significant correlations ranging from 0.70 to 0.98 (all p < 0.01) were found. The interrater reliability ranged from good to excellent (ICC(2,2) = 0.75-0.98). The results are encouraging for researchers and clinical practitioners as the investigated stiffness measurement tools are easy-to-use and comparatively affordable.

Effects of a seat-integrated mobilization system on long-haul truck drivers motion activity, muscle stiffness and discomfort during a 4.5-h simulated driving task

OBJECTIVE

The aim of this study is to evaluate the effects of a seat-integrated mobilization system on motion activity, muscle stiffness and discomfort during prolonged driving.

METHOD

During a 4.5-h driving task, motion activity, muscle stiffness and discomfort (measured subjectively and objectively) of long-haul truck drivers were determined and compared intra-individually in a test condition with mobilization (seat-integrated stimulation) and a control condition under standardized conditions in a simulated driving study (N = 16).

RESULTS

In the experimental condition, participants showed a significantly increased motion activity and a reduced muscle stiffness compared to the control condition. Furthermore, discomfort occurred significantly more frequently in the control condition.

CONCLUSION

The mobilization system increased motion activity and reduced discomfort as well as muscle stiffness. Therefore, it provides considerable potential to counteract negative effects of prolonged sitting and to promote truck driver's health.

Reliability of a New Indentometer Device for Measuring Myofascial Tissue Stiffness

Changes in tissue stiffness are associated with pathological conditions such as myofascial pain and increased risk of muscle injury. Furthermore, they have been shown to modify performance indicators such as running economy or jump height. Indentometry is an affordable way to assess tissue stiffness. However, to date, there is a paucity of studies examining the measurement properties of available devices. With this trial, we aimed to evaluate the reliability of the “IndentoPro”. Two investigators repeatedly measured the stiffness of the lateral head of the gastrocnemius muscle in healthy participants (N = 35), using 5 and 10 mm indentation depths. Intraclass Correlation Coefficients (ICC) revealed moderate inter-rater reliability (5 mm: ICC3,1 0.74, 95%CI = 0.54 to 0.86, p < 0.001; 10 mm: ICC3,1 0.59, 95%CI = 0.27 to 0.78, p < 0.001) and good intra-rater reliability (5 mm: ICC3,1 0.84, 95%CI = 0.71 to 0.92, p < 0.001; 10 mm: ICC3,1 0.83, 95%CI = 0.69 to 0.91, p < 0.001). No correlations between age, height, weight, BMI, skinfold thickness and myofascial tissue stiffness were observed (p > 0.5). In conclusion, the IndentoPro is reliable in assessing calf tissue stiffness, but the predictors of stiffness remain unclear.

Effects of Core Stabilization Exercise Programs on Changes in Erector Spinae Contractile Properties and Isokinetic Muscle Function of Adult Females with a Sedentary Lifestyle

This study aimed to investigate the effect of core stabilization exercises on the contractile properties and isokinetic muscle function of adult females with a sedentary lifestyle. We enrolled 105 adult females. Tensiomyography was performed on the erector spinae, and the isokinetic muscular functional test was performed on the trunk at an angular velocity of 60°/s and 90°/s. All participants performed the exercise for 60 min per day, 3 times a week, for 7 weeks. A Wilcoxon signed-rank test was performed at a significance level of 0.05. Tensiomyography (TMG) of the erector spinae revealed no significant post-exercise change in the contraction time; however, there was a significant post-exercise increase in the maximum radial displacement and mean velocity until 90% of the TMG was displaced. Additionally, the isokinetic muscular functional test of the trunk revealed a significant post-exercise increase in almost all variables. Our findings demonstrated that the core stabilization exercise reduced stiffness in the erector spinae, increased the velocity of erector spinae contraction, and effectively improved the isokinetic muscular function of the trunk.

Myofascial Tissue and Depression

Background

The myofascial system plays a fundamental role in the mechanics of the body, in body tension regulation and the etiology of pathological states like chronic pain. Moreover, it contains contractile elements and preliminary evidence suggests that its properties are linked to psychological factors. The aim of the present research was to investigate characteristics of the myofascial tissue in patients with Major Depressive Disorder (MDD) and to examine whether the state of the myofascial tissue causally affects pathopsychological processes in MDD.

Methods

In Study 1, stiffness and elasticity of the myofascial tissue of 40 inpatients suffering from MDD measured with a tissue compliance meter were compared with those of 40 matched never-depressed participants. In Study 2, 69 MDD patients were randomly assigned to single-session self-myofascial release intervention (SMRI) or a placebo intervention. Effects on memory bias and affect were investigated.

Results

Results showed that MDD patients displayed heightened stiffness and reduced elasticity of the myofascial tissue and that patients in the SMRI group showed a reduced negative memory bias and more positive affect compared to patients in the placebo condition.

Conclusions

The preliminary results of our studies indicate that the myofascial tissue might be part of a dysfunctional body-mind dynamic that maintains MDD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10608-021-10282-w.

Sitting for Too Long, Moving Too Little: Regular Muscle Contractions Can Reduce Muscle Stiffness During Prolonged Periods of Chair-Sitting

In modern Western societies, sedentary behavior has become a growing health concern. There is increasing evidence that prolonged sitting periods can be associated with musculoskeletal disorders. While it is generally recognized that back muscle activity is low during chair-sitting, little is known about the consequences of minor to no muscle activity on muscle stiffness. Muscle stiffness may play an important role in musculoskeletal health. This study investigated the effects of regular muscle contractions on muscle stiffness in a controlled experiment in which participants sat for 4.5 h. Neuromuscular electrical stimulation in the lumbar region of the back was applied to trigger regular muscle contractions. Using stiffness measurements and continuous motion capturing, we found that prolonged sitting periods without regular muscle contractions significantly increased back muscle stiffness. Moreover, we were able to show that regular muscle contractions can prevent those effects. Our results highlight the importance of consistent muscle activity throughout the day and may help explain why prolonged periods of chair-sitting increase the susceptibility to common pathological conditions such as low back pain.

The Rolf Method of Structural Integration on Fascial Tissue Stiffness, Elasticity, and Superficial Blood Perfusion in Healthy Individuals: The Prospective, Interventional Study

Introduction: There are multiple theories surrounding the physiological impact of structural integration (SI) with little evidence or research corroborating any of these. The aim of the study was to assess the effectiveness of 10 sessions of SI on fascial tissue (FT) superficial blood perfusion, stiffness, and elasticity in 13 healthy women.

Methods: This was a prospective, interventional study. The primary outcome measures were FTs’ superficial blood perfusion, stiffness, and elasticity of bilateral selected FT points on the body. Data were collected before and after 10 sessions of SI intervention. Statistical analysis was performed using the non-parametric Wilcoxon test (intragroup comparison).

Results: The superficial blood perfusion increased significantly in the most selected FT points on the body (p < 0.05). SI interventions produced significant decreases in selected points (brachioradialis, biceps brachii, and trapezius; p < 0.05) of FT stiffness and significant increases in elasticity (brachioradialis, biceps brachii, triceps surae, and trapezius; p < 0.05), especially in the FT of the right (dominant) upper limb.

Conclusion: A 10-session of SI demonstrated positive effects on increasing superficial blood perfusion contributed to a decrease in FT stiffness and an increase in elasticity properties in the dominant upper limb. Data collection for this study is currently underway, and the trial is registered at ISRCTN.com with the identifier: ISRCTN46707309.

Sedentary behaviour at work increases muscle stiffness of the back: Why roller massage has potential as an active break intervention

There is increasing evidence that subjects who are exposed to long sitting periods suffer from musculoskeletal discomfort and back pain. The underlying mechanism and effective prevention strategies are still largely unknown. In this study, muscle stiffness of the back was measured in 59 office workers who followed their usual desk work regime for 4.5 h in a sitting posture. The sitting period was either followed by an 8-min roller massage intervention or a controlled standing task. Results showed that muscle stiffness increased significantly after the 4.5 h sitting period. When the sitting period was followed by roller massage, the stiffness values dropped slightly below baseline stiffness. In contrast, the stiffness values remained increased when the sitting period was followed by controlled standing. This study indicates that short-duration tissue manipulation can be an effective active break between prolonged sitting periods to prevent musculoskeletal issues, such as musculoskeletal discomfort and back pain.

Development of a Noninvasive Skin Evaluation Method for Lower Limb Lymphedema

Background: The skin's condition is altered in lymphedema patients, and evaluating this change is important. Some noninvasive methods for evaluating skin condition have been reported, especially in upper limb lymphedema. However, evaluating the skin in lower limb lymphedema remains challenging and is often limited to palpation. We aimed to develop a noninvasive skin evaluation method for lower limb lymphedema patients. Methods and Results: Twenty-five lower limb lymphedema patients were included. Skin induration and elasticity were measured using Indentometer^® IDM 400 and Cutometer^® MPA580. The relationship between the properties of skin from the healthy forearm and thigh, those of the affected thigh, and age was analyzed. Predicted skin induration age (IA) and elasticity age (EA) were calculated from the forearm, whereas actual values were calculated from the thigh, and the differences (ΔIA and ΔEA) were assessed. Patients were classified according to the International Society of Lymphology clinical staging system, and the differences in ΔIA and ΔEA were analyzed among the three groups (healthy, stage I/IIa, and stage IIb/III). Skin biopsy was performed in five unilateral lower limb lymphedema patients, and the dermal elastic fiber area was determined using microscopy with Elastica van Gieson staining. ΔEA significantly increased with disease progression, but ΔIA did not change significantly. Microscopy revealed elastic fiber filamentous changes, with decreased elastic fiber areas in lymphedema-affected skin. Conclusion: To our knowledge, this is the first report to evaluate lower limb skin elasticity in lymphedema quantitatively and noninvasively. ΔEA is useful for evaluating skin condition progression in lymphedema patients.

Active contractile properties of fascia

The ubiquitous network of fascial tissues in the human body is usually regarded as a passive contributor to musculoskeletal dynamics. This review aims to highlight the current understanding of fascial stiffness regulation. Notably the ability for active cellular contraction which may augment the stiffness of fascial tissues and thereby contribute to musculoskeletal dynamics. A related narrative literature search via PubMed and Google Scholar reveals a multitude of studies indicating that the intrafascial presence of myofibroblasts may enable these tissues to alter their stiffness. This contractile tissue behavior occurs not only in several pathological fibrotic contractures but has also been documented in normal fasciae. When viewed at time frames of seconds and minutes the force of such tissue contractions is not sufficient for exerting a significant effect on mechanical joint stability. However, when viewed in a time-window of several minutes and longer, such cellular contractions can impact motoneuronal coordination. In addition, over a time frame of days to months, this cellular activity can induce long-term and severe tissue contractures. These findings tend to question the common clear distinction between active tissues and passive tissues in musculoskeletal dynamics. Clin. Anat. 32:891-895, 2019. © 2019 Wiley Periodicals, Inc.

Fascial tissue research in sports medicine: from molecules to tissue adaptation, injury and diagnostics: consensus statement

The fascial system builds a three-dimensional continuum of soft, collagen-containing, loose and dense fibrous connective tissue that permeates the body and enables all body systems to operate in an integrated manner. Injuries to the fascial system cause a significant loss of performance in recreational exercise as well as high-performance sports, and could have a potential role in the development and perpetuation of musculoskeletal disorders, including lower back pain. Fascial tissues deserve more detailed attention in the field of sports medicine. A better understanding of their adaptation dynamics to mechanical loading as well as to biochemical conditions promises valuable improvements in terms of injury prevention, athletic performance and sports-related rehabilitation. This consensus statement reflects the state of knowledge regarding the role of fascial tissues in the discipline of sports medicine. It aims to (1) provide an overview of the contemporary state of knowledge regarding the fascial system from the microlevel (molecular and cellular responses) to the macrolevel (mechanical properties), (2) summarise the responses of the fascial system to altered loading (physical exercise), to injury and other physiological challenges including ageing, (3) outline the methods available to study the fascial system, and (4) highlight the contemporary view of interventions that target fascial tissue in sport and exercise medicine. Advancing this field will require a coordinated effort of researchers and clinicians combining mechanobiology, exercise physiology and improved assessment technologies.