Grade 4 in manual muscle testing: the problem with submaximal strength assessment

Principal component analysis biplot visualization of electromyogram features for submaximal muscle strength grading

BACKGROUND

Submaximal muscle strength grading is clinically significant to monitor the progress of rehabilitation. Especially muscle strength grading of core back muscles is challenging using the conventional manual muscle testing (MMT) methods. The muscles are crucial to recovery from back pain, spinal cord injury, stroke and other related diseases. The subjective nature of MMT, adds more ambiguity to grade fine progressions in submaximal strength levels involving 4-, 4 and 4+ grades. Electromyogram (EMG) has been widely used as a quantitative measure to provide insight into the progress of muscle strength. However, several EMG features have been reported in previous studies, and the selection of suitable features pertaining to the problem has remained a challenge.

METHOD

Principal Component Analysis (PCA) biplot visualization is employed in this study to select EMG features that highlight fine changes in muscle strength spanning the submaximal range. Features that offer maximum loading in the principal component subspace, as observed in the PCA biplot, are selected for grading submaximal strength. The performance of the proposed feature set is compared with conventional Principal Component (PC) scores. Submaximal muscle strength grades of 4-, 4, 4+ or 5 are assigned using K-means and Gaussian mixture model clustering methods. Clustering performance of the two feature selection methods is compared using the silhouette score metric.

RESULTS

The proposed feature set from biplot visualization involving Root Mean Square (RMS) EMG and Waveform Length in combination with Gaussian Mixture Model (GMM) clustering method was observed to offer maximum accuracy. Muscle-wise mean Silhouette Index (SI) scores (p < 0.05) of .81, .74 (Longissimus thoracis left, right) and .73, .77 (Iliocostalis lumborum left, right) were observed. Similarly grade wise mean SI scores (p < 0.05) of .80, .76, .73, and .981 for grades 4-, 4, 4+, and 5 respectively, were observed.

CONCLUSION

The study addresses the problem of selecting minimum features that offer maximum variability for EMG assisted submaximal muscle strength grading. The proposed method emphasizes using biplot visualization to overcome the difficulty in choosing appropriate EMG features of the core back muscles that significantly distinguishes between grades 4-, 4, 4+ and 5.

Rehabilitation of the painful shoulder

Managing the painful shoulder in overhead athletes can be difficult because of a lack of time-loss injuries in overhead sports and focusing primarily on either pathoanatomic causes or movement impairments. Although managing the painful shoulder can be challenging, the combination of identifying pathoanatomic causes with movement impairments can provide a more focused rehabilitation approach directed at the causes of shoulder pain. Understanding the potential influence of scapular positioning as well as mobility and/or strength impairments on shoulder pain can help clinicians develop more directed rehabilitation programs. Furthermore, sports-specific methods such as long toss or the use of weighted balls for achieving physiological or performance-based gains have limited empirical evidence regarding their clinical and performance-based benefits, which may impede the rehabilitation process. Applying a comprehensive evaluation approach prior to and throughout the treatment process can assist clinicians with selecting the most appropriate treatment based on patient need. Reconsidering traditional treatments based on existing evidence may help refine the treatment process for overhead athletes with shoulder pain.

Criteria-based return to sport testing after open Latarjet reveals residual deficits and can be utilized for sports clearance with excellent outcomes at mean 3.6 year follow-up: A small case series of competitive athletes

OBJECTIVE

The purpose of this study was to assess the use of a criteria-based return to sport (CBRTS) test to evaluate readiness for return to play (RTP) in competitive athletes that underwent open Latarjet.

DESIGN

Retrospective case series.

METHODS

Ten competitive athletes (mean age 19.9 years) treated with open Latarjet for recurrent glenohumeral instability underwent CBRTS testing at a mean of 5.3 months postoperatively. Testing consisted of four components: 1. isometric strength, 2. isokinetic strength, 3. endurance, and 4. function. Patients failing 0 or 1 component of the test were cleared to RTP. Patients failing multiple components underwent additional deficit-based rehabilitation.

RESULTS

Of the 10 patients that tested, 4 passed their overall CBRTS test and were cleared to RTP. The remaining 6 patients failed the overall CBRTS test. Seven patients (70%) failed at least one section of the strength testing, two patients (20%) failed endurance testing, and two patients (20%) failed functional testing. At final follow-up (mean 3.6 years), 1 patient had recurrent instability (10%) and 9 patients returned to play (90%).

CONCLUSIONS

CBRTS testing may be clinically useful for return to play clearance decisions after open Latarjet procedure, as it can reveal deficits that may not be identified with time-based clearance alone.

Do the Testing Posture and the Grip Modality Influence the Shoulder Maximal Voluntary Isometric Contraction?

Assessing and monitoring shoulder strength is extremely important during rehabilitation. A fixed dynamometer represents a valid and inexpensive assessment method. However, it has not been studied whether posture and grip modality influence shoulder muscle strength. The aim of this study was to compare shoulder strength values between sitting and standing positions and between the handle and cuff grip modalities. A total of 40 volunteers were divided into a posture (PG) and a handle-cuff group (HCG). Participants in the PG were asked to perform a maximum voluntary isometric contraction (MVIC) for shoulder flexion, extension, ab-adduction, and intra-extra rotation in standing and sitting positions. The HCG participants were tested in a standing position while holding a handle or with a cuff around their wrist. PG showed higher forces in the standing position for shoulder flexion (p = 0.009); internal rotation showed higher values in the sitting position (p = 0.003). ER/IR ratio was significantly higher in the standing position (p < 0.001). HCG showed higher significant forces during cuff modality in all positions and grip modalities, including the ER/IR ratio (p < 0.05). Different body positions and grip modalities influenced the assessment of shoulder strength as recorded by a fixed dynamometer; therefore, these factors should be carefully considered when carrying out a shoulder strength assessment, and we encourage the development of assessment guidelines to make future clinical trial results comparable.

Inter-rater reliability of the Rasch-modified medical research council scoring criteria for manual muscle testing in neuromuscular diseases

It was argued that researchers and clinicians are not able to make judgments between most categories of the original Medical Research Council (MRC) scale and that a modified short version would reach higher agreement levels. We aimed to assess the inter-rater reliability for both the original and the Rasch-modified MRC scoring criteria of Manual Muscle Strength tests (MMSt) in patients with neuromuscular diseases. Two MRC scoring criteria were used to score muscle strength using MMSt in 40 muscle groups of the upper and lower limbs in patients with neuromuscular disorders. Three investigators performed the evaluations; the order of the MMSt and the use of the scales were performed according to the preferences of the investigators. The agreement coefficient (Gwet's AC₂ ) was used to compute the reliability. Sixty patients (mean age of 39.3 years ± 15.2) with neuromuscular diseases were included. The mean AC₂ for the muscle groups of the upper limbs ranged from 0.82 to 0.96 using the modified MRC scale and from 0.86 to 0.96 using the original MRC scale. The AC₂ for the lower limb muscle groups ranged from 0.80 to 0.91 (modified MRC scale) and from 0.87 to 0.93 (original MRC scale). These values might be interpreted as "almost perfect agreement" with no significant differences between the scales. The results indicate that both MRC scoring criteria have significant reliability among trained observers. Moreover, the Rasch-modified MRC scale is as reliable as the original MRC scale and can be used in future clinical studies.

Toward Improving the Prediction of Functional Ambulation After Spinal Cord Injury Though the Inclusion of Limb Accelerations During Sleep and Personal Factors

OBJECTIVE

To determine if functional measures of ambulation can be accurately classified using clinical measures; demographics; personal, psychosocial, and environmental factors; and limb accelerations (LAs) obtained during sleep among individuals with chronic, motor incomplete spinal cord injury (SCI) in an effort to guide future, longitudinal predictions models.

DESIGN

Cross-sectional, 1-5 days of data collection.

SETTING

Community-based data collection.

PARTICIPANTS

Adults with chronic (>1 year), motor incomplete SCI (N=27).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Ambulatory ability based on the 10-m walk test (10MWT) or 6-minute walk test (6MWT) categorized as nonambulatory, household ambulator (0.01-0.44 m/s, 1-204 m), or community ambulator (>0.44 m/s, >204 m). A random forest model classified ambulatory ability using input features including clinical measures of strength, sensation, and spasticity; demographics; personal, psychosocial, and environmental factors including pain, environmental factors, health, social support, self-efficacy, resilience, and sleep quality; and LAs measured during sleep. Machine learning methods were used explicitly to avoid overfitting and minimize the possibility of biased results.

RESULTS

The combination of LA, clinical, and demographic features resulted in the highest classification accuracies for both functional ambulation outcomes (10MWT=70.4%, 6MWT=81.5%). Adding LAs, personal, psychosocial, and environmental factors, or both increased the accuracy of classification compared with the clinical/demographic features alone. Clinical measures of strength and sensation (especially knee flexion strength), LA measures of movement smoothness, and presence of pain and comorbidities were among the most important features selected for the models.

CONCLUSIONS

The addition of LA and personal, psychosocial, and environmental features increased functional ambulation classification accuracy in a population with incomplete SCI for whom improved prognosis for mobility outcomes is needed. These findings provide support for future longitudinal studies that use LA; personal, psychosocial, and environmental factors; and advanced analyses to improve clinical prediction rules for functional mobility outcomes.

Subterminal key pinch dynamometry: a new method to quantify strength deficit in ulnar nerve paralysis

Precise pre- and postoperative assessments are fundamental to recording the quality of recovery after ulnar nerve repair. Because of its imprecision, manual muscle testing is being replaced by dynamometry to measure grasping and key-pinch strengths. However, both grasping and key pinch are dependent not only on the ulnar nerve but also the median and radial nerves. We propose to measure strength using a new sort of pinch, called the 'subterminal key pinch'. Strength was measured using a commercially available pinch meter. Patients applied pressure on the dynamometer with the interphalangeal joint of the thumb, maintaining the joint in extension to avoid enhancement of strength by the flexor pollicis longus. We examined 17 patients before ulnar nerve repair. Preoperatively, grasping strength was 46% of normal, while key pinch was 58%, pinch-to-zoom strength was 26% and subterminal key pinch only 7%. Subterminal key pinch was the most affected pinch with a strength deficit of over 90%.Level of evidence: IV.

Factors associated with gait outcomes in patients with traumatic lumbosacral plexus injuries

PURPOSE

Lumbosacral plexus injuries usually occur in patients with severe, multiple traumas requiring intensive care, affecting gait function. The purpose of the present study was to identify the initial factors associated with gait outcome in lumbosacral plexus injuries caused by traumas.

METHODS

We retrospectively identified 664 patients with pelvic fractures caused by trauma between 2006 and 2017. The lumbosacral plexus injuries were electrodiagnostically confirmed in 30 patients (4.5%). Demographic, injury-related, fracture-related and electrodiagnostic factors were compared between patients with long-term unassisted gait outcomes to those with assisted gait outcomes, with an average of 27 months elapsing after the trauma.

RESULTS

Eleven patients (36.7%) remained in the assisted gait group during the follow-up period. Complex pelvic trauma, rather than the severity of trauma to the entire body, was associated with a poor gait outcome. Among the various causes of injury, pedestrians struck by vehicles were associated with assisted gait outcomes. The number of anatomic locations involved in pelvic fractures, pelvic ring instability by Tile classification, and the proportion of unstable sacral fractures were higher in patients with assisted gait outcomes compared with those having unassisted gait outcomes. Weaknesses in the initial hip extensor, knee flexor, ankle dorsiflexor and ankle plantar flexor were observed significantly more often in patients with assisted gait outcomes. The Dumitru and Wilbourn's scale of the anterior and posterior sacral plexus was significantly higher in the assisted gait group.

CONCLUSIONS

Gait outcome after lumbosacral plexus injury is associated with the range and stability of the pelvic fracture and the severity of the anterior and posterior sacral plexus injury. Poor gait outcome was associated with the severity of the trauma to the pelvis rather than that to the entire body.

Portable fixed dynamometry to quantify ankle dorsiflexion force

INTRODUCTION

Quantifying muscle strength is critical in clinical and research settings. A rapid and objective method is ideal. The primary objective of this study was to examine the reliability of a novel device, the rapid objective quantification- tibialis anterior (ROQ-TA), which quantifies the dorsiflexion force of the tibialis anterior, and to assess its validity against isokinetic dynamometry (IKD).

METHODS

Ankle dorsiflexion of 20 healthy subjects was assessed by 3 modalities, ROQ-TA, manual muscle testing, and isokinetic dynamometry, over 2 testing sessions.

RESULTS

The intraclass correlation coefficient [ICC_(2,1) ] for reliability was 0.872 (0.677-0.949) for the ROQ-TA and 0.892 (0.728-0.957) for IKD. For validity, the ICC_(2,1) values for the ROQ-TA and IKD were in good agreement, with 0.672 (0.17-0.87) in the first testing session and 0.769 (0.42-0.91) in the second session.

DISCUSSION

The ROQ-TA is a valid and reliable device to test ankle dorsiflexion force in a healthy population. Muscle Nerve, 2018.

Considerations and Practical Options for Measuring Muscle Strength: A Narrative Review

Muscle strength impairments are related to mobility limitations and other untoward outcomes. This narrative review, therefore, describes considerations relative to the definition and measurement of muscle strength. Thereafter, practical options for measuring muscle strength are described and their clinimetric properties are delineated. Information provided herein may help students, clinicians, and researchers select the strength tests best suited to their research needs and limitations.

Isometric knee extension force in Japanese type 2 diabetic patients without apparent diabetic polyneuropathy: Data from the Multicenter Survey of the Isometric Lower Extremity Strength in Type 2 Diabetes study

OBJECTIVES

To determine standard reference values for isometric knee extension force using a cohort of Japanese type 2 diabetic patients without diabetic polyneuropathy.

METHODS

Patient data were collected from the Multicenter Survey of the Isometric Lower Extremity Strength in Type 2 Diabetes study and compared with previously published data of healthy control subjects. In total, we enrolled 898 patients with type 2 diabetes aged 30-87 years, who did not have diabetic polyneuropathy. The control group included 510 healthy subjects aged 30-88 years. Maximum isometric knee extension force (KEF) values were obtained by using a hand-held dynamometer with belt stabilization. In addition, KEF (kgf) was adjusted for bodyweight (kg) to calculate %KEF.

RESULTS

KEF and %KEF decreased with age in both patients with diabetes and healthy control subjects. The mean values of KEF and %KEF in patients with diabetes were reduced by 9.7% and 20.8%, respectively, in males, and by 11.6% and 23.0%, respectively, in females compared to the values in healthy control subjects.

CONCLUSION

KEF and %KEF in patients with type 2 diabetes without diabetic polyneuropathy may reduce by approximately 10% and 20%, respectively, compared to these values in healthy control subjects. This study provides reference values for isometric KEF with respect to sex in a population covering a wide age range.

Assessment of lower extremity muscle mass, muscle strength, and exercise therapy in elderly patients with diabetes mellitus

The increase in the proportion of elderly people in the population is one of the most remarkable sociodemographic phenomena of the twenty-first century. The number of patients with diabetes is also increasing worldwide with this demographic change. Given these facts, consideration of the problems the general elderly population is facing in the management of diabetes is essential. In this review article, we focus on sarcopenia, which is the decrease in lower extremity muscle mass and muscle strength accompanying aging, describe the relationship between sarcopenia and diabetes, and highlight the specific factors through which diabetes contributes to loss of muscle strength. The quantitative methods for evaluating lower extremity muscle strength will also be described. These methods hold the key to assessing the effectiveness of exercise therapy and optimizing the assessment of the degree of autonomy in the activities of daily living. Exercise is one of the basic treatments for type 2 diabetes and may also prevent and improve sarcopenia. This review discusses the aspects common to the two health conditions and elucidates the effectiveness and necessity of exercise as a preventive measure against diabetes among the elderly.

Using 4+ to grade near-normal muscle strength does not improve agreement

Background

Manual assessment of muscle strength is often graded using the ordinal Medical Research Council (MRC) scale. The scale has a number of inherent weaknesses, including poorly defined limits between grades ‘4’ and ‘5’ and very large differences in the span of muscle strength encompassed by each of the six grades. It is not necessarily obvious how to convert a manual muscle test finding into an MRC grade. Several modifications which include intermediate grades have been suggested to improve the MRC scale and the current study examines whether agreement improves and variation in ratings decrease, with an intermediate grade between ‘4’ and ‘5’, in circumstances where such a grade would seem appropriate. The present study examined the hypothesis, that a modified MRC-scale which included the commonly used ‘4+’ option, resulted in greater agreement between clinicians compared to the standard MRC-scale.

Method

A questionnaire containing five simple clinical cases were distributed to a large convenience sample of chiropractors in Northern Europe, with instructions to grade the described muscle strength findings using the MRC scale. The scale was adapted (with/without an intermediate ‘4+’ grade) depending on the preference of the individual respondent. The cases were designed in such a way as to suggest a muscle weakness in the grey area between ‘4’ and ‘5’, i.e. grade ‘4+’ on the modified MRC scale.

Results

A total of 225 questionnaires were returned (7% response rate). The average percentage agreement (across cases) in the standard MRC group was 64% [range 51%: 73%] (grade ‘4’ in all cases). In the modified MRC group, the corresponding findings was 48% [38%: 74%] (grade ‘4’ or ‘4+’ in all cases). The mean average deviation analogue in the standard MRC group was 0.34 (range 0.34: 0.40), compared to 0.51 (range 0.39: 0.73) in the modified MRC group, indicating greater dispersion of scores in the modified MRC group. The Fleiss kappa was 0.02 (p < 0.001) and 0.13 (p < 0.001), respectively.

Conclusions

Contrary to the original hypothesis, introduction of a ‘4+’ grade did not clearly improve agreement or variability of ratings, despite eliminating the physical muscle testing by providing written descriptions of test findings and specifically designing these to suggest a weakness of grade ‘4+’.

Electronic supplementary material

The online version of this article (10.1186/s12998-017-0159-6) contains supplementary material, which is available to authorized users.

Does 6-Month Home Caregiver-Supervised Physiotherapy Improve Post-Critical Care Outcomes?: A Randomized Controlled Trial

OBJECTIVE

This study aims to determine whether a 6-month home physiotherapy program can improve outcomes in critical care survivors.

DESIGN

Forty-eight consecutive patients were randomized. The treatment group underwent 2 sessions/day of breathing retraining and bronchial hygiene, physical activity (mobilization, sit-to-stand gait, limb strengthening), and exercise re-conditioning whereas controls underwent standard care. Maximum inspiratory/expiratory pressures (MIP/MEP), forced volumes, blood gases, dyspnea, respiratory rate, disability, peripheral force measurements, perceived health status (Euroquol-5D), patient adherence/satisfaction, safety, and costs were assessed.

RESULTS

Outcomes of treatment versus controls: MIP 14 ± 17 vs. -0.2 ± 14 cm H2O, MEP 27 ± 27 vs. 6 ± 21 cm H2O both P < 0.03; in addition, quality of life (Euroquol-5D) (P = 0.04), FEV1 (P = 0.03), dyspnea (P = 0.002), and respiratory rate (P = 0.009) were significantly improved for treated cardiorespiratory patients only. Eighty-three percent of the treated patients were decannulated versus 14% of controls (P = 0.01). Compliance was high (74 ± 25%) and there were no side effects. The majority (87.4%) expressed satisfaction with the program. Treatment cost was 459&OV0556;/patient/month.

CONCLUSIONS

Carrying over regular bronchial hygiene techniques, physical activity, and exercise into the home after long critical care stays is safe and has a beneficial effect on respiratory muscles, decannulation, pulmonary function, and quality of life.

Reliability of lower extremity muscle strength measurements with handheld dynamometry in stroke patients during the acute phase: a pilot reliability study

[Purpose] No literature has described a suitable method for measuring muscle strength in a supine position during acute phase after stroke. This study investigated the feasibility and reliability of using a commercial handheld dynamometer to measure the muscle strengths of the hip flexor, knee extensor, and dorsiflexor in the supine position with a modified method for patients at a stroke intensive care center within 7 days of stroke onset. [Subjects and Methods] Fifteen persons with acute stroke participated in this cross-sectional study. For each patient, the muscle strengths of the hip flexors, knee extensors, and dorsiflexors were measured twice by two testers on the same day. Each patient was re-tested at the same time of day one day later. Inter-rater and test-retest reliability were then determined by the intraclass correlation coefficients (ICCs). [Results] For the three muscle groups, the inter-rater reliability ICCs were all 0.99 and the test-retest reliability ICCs were greater than 0.85. The investigated method thus has good inter-rater reliability and high agreement between the test-retest measurements, with acceptable measurement errors. [Conclusion] The modified method using a handheld dynamometer to test the muscle strength of acute stroke patients is a feasible and reliable method for clinical use.

A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.'s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: M_f)—the static muscular moment to support a limb segment against gravity—from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, M_m) was calculated. Body weight and limb segment length (thigh and lower leg length) were measured, and M_f was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between M_f and M_m in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only.

Lower limb muscle strength impairment in late-onset and adult myotonic dystrophy type 1 phenotypes

INTRODUCTION

Lower limb strength has never been characterized separately for late-onset and adult myotonic dystrophy type 1 (DM1) phenotypes.

METHODS

The purpose of this study was to: (1) describe and compare lower limb strength between the 2 DM1 phenotypes; and (2) compare the impairment profiles obtained from 2 assessment methods [manual (MMT) and quantitative (QMT) muscle testing] among 107 patients.

RESULTS

Both MMT and QMT showed more pronounced weakness in the adult phenotype. In the late-onset phenotype, although MMT showed normal strength, QMT revealed a loss of 11.7%-20.4%. Participants with grade 1 or 2 on the Muscle Impairment Rating Scale had weakness detected using QMT, which suggests earlier muscle impairment than MMT alone would suggest.

CONCLUSIONS

To avoid muscle wasting, physical activity recommendations should be made for the late-onset phenotype and in the early stages of the disease for the adult phenotype. MMT is not recommended for use in clinical trials. Muscle Nerve 56: 57-63, 2017.

Manual muscle testing: does it meet the standards of an adequate screening test?

Objective: To describe the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of manual muscle testing.

Design: Secondary analysis of cross-sectional strength data.

Setting: Acute rehabilitation unit.

Participants: Convenience sample of 107 consecutive qualifying rehabilitation inpatients.

Intervention: Not applicable.

Main outcome measures: Knee extension forces measured by manual muscle testing and hand-held dynamometry.

Results: The ability of manual muscle testing to detect 15, 20, 25 and 30% between-side differences and deficits in knee extension force was described. Although the specificity of manual muscle testing was acceptable (mostly>80%), its sensitivity to differences between sides and to deficits relative to normal never exceeded 75%. Its diagnostic accuracy was never greater than 78%.

Conclusion: The results of this study cast doubt on the suitability of manual muscle testing as a screening test for strength impairments.

Results of wrist extension reconstruction in C5-8 brachial plexus palsy by transferring the pronator quadratus motor branch to the extensor carpi radialis brevis muscle

OBJECT The objective of this study was to report the results of pronator quadratus (PQ) motor branch transfers to the extensor carpi radialis brevis (ECRB) motor branch to reconstruct wrist extension in C5-8 root lesions of the brachial plexus. METHODS Twenty-eight patients, averaging 24 years of age, with C5-8 root injuries underwent operations an average of 7 months after their accident. In 19 patients, wrist extension was impossible at baseline, whereas in 9 patients wrist extension was managed by activating thumb and wrist extensors. When these 9 patients grasped an object, their wrist dropped and grasp strength was lost. Wrist extension was reconstructed by transferring the PQ motor to the ECRB motor branch. After surgery, patients were followed for at least 12 months, with final follow-up an average of 22 months after surgery. RESULTS Successful reinnervation of the ECRB was demonstrated in 27 of the 28 patients. In 25 of the patients, wrist extension scored M4, and in 2 it scored M3. CONCLUSIONS In C5-8 root injuries, wrist extension can be predictably reconstructed by transferring the PQ motor branch to reinnervate the ECRB.

The intra- and inter-rater reliabilities of lower extremity muscle strength assessment of healthy adults using a hand held dynamometer

[Purpose] The purpose of this study was to examine the intra- and inter-rater reliabilities of lower extremity muscle strength assessment of healthy adults using hand held dynamometer. [Subjects and Methods] A total of 55 students (19 males and 36 females) in Y University in Gyeongsangnam-do, South Korea participated in this study. Lower extremity muscle strength was measured using a hand-held dynamometer (Commander Muscle Tester, JTech, USA). Flexion and extension strengths of the hip joint, the knee joint, and the ankle joint were measured. [Results] The intra-rater reliabilities were excellent (above 0.9) for the flexion and extension strengths of the ankle, knee, and hip joints. The inter-rater reliabilities were also excellent (above 0.8) for the flexion and extension strengths of the ankle, knee, and hip joint. [Conclusion] Lower extremity muscle strength assessment using a hand-held dynamometer provided consistent results when conducted by different examiners and when measured several times. Therefore, this method is a useful way of deriving objective and quantitative measurement values.

Difference, significant difference and clinically meaningful difference: The meaning of change in rehabilitation

The valid confirmation of a positive change (improvement) in a patient’s health status due to intervention has been at the core of medicine and rehabilitation since their very inception as clinicians always aspired to ensure that treating their patients had led to successful outcomes both in acute and chronic conditions. However what is change: either improvement or worsening (aggravation), is a complicated issue which involves clinical as well as statistical considerations. Change invariably relates to a difference in some measurable entity and almost always it relates to a time span. The confirmation of clinical change is important both for varying the treatment course (if necessary) and for the termination of treatment when the latter has reached wither its prescribed objective or a plateau. Since in the context of rehabilitation, the outcome measures (OM) are strongly linked to performance, determination of change in the latter is confounded by many factors, collectively known as the error of measurement, which render a decision regarding clinically meaningful change, highly involved. This is further complicated by the stability of the observed OM, the so-called reproducibility of the OM, and the accuracy of the measurement instrument. The higher the reproducibility the lower is the error. Moreover, in order to proclaim change, in most cases a positive one, it is necessary for the difference in outcome scores (i.e. the change) to surpass the error of measurement, in varying degree of rigor. This paper describes selected methods associated with determination of change and focuses predominantly on the difference between a simple difference in scores (‘simple change’), a significant difference in scores and the so-called clinically meaningful change in scores which is considered today as the benchmark for confirmation of a real change.

The association between unilateral heel-rise performance with static and dynamic balance in community dwelling older adults

As a measure of both strength and muscle endurance of the plantar flexors, the unilateral heel rise (UHR) test has been suggested as a method to evaluate balance capabilities in older adults. Thus, the purpose of this study was to examine the association between UHR performance with biomechanical measures of balance in seniors. Twenty-two older adults completed two testing sessions. The first visit included UHR performance; the second visit included dynamic and static motion analysis. UHR performance was significantly associated with dynamic balance capability as measured by medial-lateral inclination angle during gait. As indicated by an analysis of center of pressure, there were significant associations between UHR performance and measures of static balance. Balance is influenced by plantar flexor performance as measured by the UHR test. We therefore suggest incorporating the UHR test in analyses of balance in seniors.

Is a sphygmomanometer a valid and reliable tool to measure the isometric strength of hip muscles? A systematic review

BACKGROUND

Muscle strength measurement is a key component of physiotherapists' assessment and is frequently used as an outcome measure. A sphygmomanometer is an instrument commonly used to measure blood pressure that can be potentially used as a tool to assess isometric muscle strength.

OBJECTIVE

To systematically review the evidence on the reliability and validity of a sphygmomanometer for measuring isometric strength of hip muscles.

METHOD

A literature search was conducted across four databases. Studies were eligible if they presented data on reliability and/or validity, used a sphygmomanometer to measure isometric muscle strength of the hip region, and were peer reviewed. The individual studies were evaluated for quality using a standardized critical appraisal tool.

RESULTS

A total of 644 articles were screened for eligibility, with five articles chosen for inclusion. The use of a sphygmomanometer to objectively assess isometric muscle strength of the hip muscles appears to be reliable with intraclass correlation coefficient values ranging from 0.66 to 0.94 in elderly and young populations. No studies were identified that have assessed the validity of a sphygmomanometer.

CONCLUSION

The sphygmomanometer appears to be reliable for assessment of isometric muscle strength around the hip joint, but further research is warranted to establish its validity.

The median nerve consistently drives flexion of the distal phalanx of the ring and little fingers: Interest in finger flexion reconstruction by nerve transfers

Surgeons believe that in high ulnar nerve lesion distal interphalangeal joint (DIP) flexion of the ring and little finger is abolished. In this article, we present the results of a study on innervation of the flexor digitorum profundus of the ring and little fingers in five patients with high ulnar nerve injury and in 19 patients with a brachial plexus, posterior cord, or radial nerve injury. Patients with ulnar nerve lesion were assessed clinically and during surgery for ulnar nerve repair we confirmed complete lesion of the ulnar nerve in all cases. In the remaining 19 patients, during surgery, either the median nerve (MN) or the anterior interosseous nerve (AIN) was stimulated electrically and DIP flexion of the ring and little fingers evaluated. All patients with high ulnar nerve lesions had active DIP flexion of the ring and little fingers. Strength scored M4 in the ring and M3-M4 in the little finger. Electrical stimulation of either the MN or AIN produced DIP flexion of the ring and little fingers. Contrary to common knowledge, we identified preserved flexion of the distal phalanx of the ring and little fingers in high ulnar nerve lesions. On the basis of these observations, nerve transfers to the AIN may provide flexion of all fingers.

Clinical predictive value of manual muscle strength testing during critical illness: an observational cohort study

INTRODUCTION

Impaired skeletal muscle function has important clinical outcome implications for survivors of critical illness. Previous studies employing volitional manual muscle testing for diagnosing intensive care unit-acquired weakness (ICU-AW) during the early stages of critical illness have only provided limited data on outcome. This study aimed to determine inter-observer agreement and clinical predictive value of the Medical Research Council sum score (MRC-SS) test in critically ill patients.

METHODS

Study 1: Inter-observer agreement for ICU-AW between two clinicians in critically ill patients within ICU (n = 20) was compared with simulated presentations (n = 20). Study 2: MRC-SS at awakening in an unselected sequential ICU cohort was used to determine the clinical predictive value (n = 94) for outcomes of ICU and hospital mortality and length of stay.

RESULTS

Although the intra-class correlation coefficient (ICC) for MRC-SS in the ICU was 0.94 (95% CI 0.85-0.98), κ statistic for diagnosis of ICU-AW (MRC-SS <48/60) was only 0.60 (95% CI 0.25-0.95). Agreement for simulated weakness presentations was almost complete (ICC 1.0 (95% CI 0.99-1.0), with a κ statistic of 1.0 (95% CI 1.0-1.0)). There was no association observed between ability to perform the MRC-SS and clinical outcome and no association between ICU-AW and mortality. Although ICU-AW demonstrated limited positive predictive value for ICU (54.2%; 95% CI 39.2-68.6) and hospital (66.7%; 95% CI 51.6-79.6) length of stay, the negative predictive value for ICU length of stay was clinically acceptable (88.2%; 95% CI 63.6-98.5).

CONCLUSIONS

These data highlight the limited clinical applicability of volitional muscle strength testing in critically ill patients. Alternative non-volitional strategies are required for assessment and monitoring of muscle function in the early stages of critical illness.

Treatment for a 14-year-old girl with Lyme disease using therapeutic exercise and gait training

BACKGROUND AND PURPOSE

Lyme disease is well documented in the literature; however, specific physical therapy interventions for the pediatric population with residual effects of Lyme disease have not been addressed. The purposes of this retrospective case report are: (1) to present an example of a therapeutic intervention for a pediatric patient in the late stages of Lyme disease with related musculoskeletal dysfunction and severely impaired quality of life, (2) to report the patient's functional outcomes from treatment, and (3) to discuss implications for treatment of patients with musculoskeletal dysfunction in the late stages of Lyme disease.

CASE DESCRIPTION

The patient was a 14-year old girl who had contracted Lyme disease 1 year prior to initiation of physical therapy. She was unable to participate with her peers in school, church, and sporting events due to significant impairments in strength (force-generating capacity), endurance, and gait; fatigue; pain; and total body tremor. Therapeutic exercise and gait training were used for treatment. The patient actively participated in managing her care by providing feedback during interventions and setting goals.

OUTCOMES

After 18 weeks of treatment, the patient achieved 96.7% of her predicted distance on the Six-Minute Walk Test with normal gait mechanics and returned to playing high school sports. She had a manual muscle test grade of 4/5 or greater in major extremity muscle groups. She returned to school and church participation with minimal total body tremor when fatigued and daily pain rated 0 to 3/10.

DISCUSSION

Therapeutic exercise and gait training may facilitate return to function in an adolescent patient with late effects of Lyme disease. Further investigation is advised to establish treatment effects in a broader population.

The concurrent validity of a hand-held versus a stationary dynamometer in testing isometric shoulder strength

STUDY DESIGN

Clinical Measurement-Validity.

INTRODUCTION

Validity of the JTech PowerTrack II hand-held dynamometer (JTech; JTech Medical, Salt Lake City, UT) for measuring shoulder strength has yet to be established.

PURPOSE OF THE STUDY

To examine the concurrent validity of isometric strength scores obtained with the JTech PowerTrack II, and on a stationary dynamometer, the LIDO WorkSET (LIDO; LoredanBiomedical, West Sacramento, CA).

METHODS

Thirty-eight subjects performed three maximal efforts of shoulder flexion, abduction, and external rotation on a single occasion on the two dynamometers. Two testers were randomly assigned to administer the tests.

RESULTS

Pearson correlations between the scores on the two dynamometers (r.0.81) indicated a good concurrent validity. Correlations were similar when the results were subdivided by tester or gender.

CONCLUSIONS

This study suggests that either the JTech PowerTrack II or LIDOWorkSET provide comparable scores for shoulder strength. Although not interchangeable because of the differences in units of measurement, the relative conclusions about strength should be similar, regardless of which instrument is used.

LEVEL OF EVIDENCE

Not applicable.

Application of the segment weight dynamic movement method to the normalization of gait EMG amplitude

This study aims at determining the applicability of a segment weight dynamic movement (SWDM) method as an alternative for normalizing gait EMGs in comparison with the conventional isometric maximal voluntary contraction (MVC) method. The SWDM method employs reference exercises, each being a dynamic, repetitive movement of a joint under the load of the segment weight (i.e., the total weight of all segments distal to the joint). EMG amplitudes of 28 healthy male subjects walking at 120 steps/min were normalized by the two methods. CV and VR were used to assess the inter-individual variability of both the normalized gait EMG for 8 muscles. The CV and VR values attained with the two methods were close to each other, as well as to those obtained by other researchers using the isometric MVC method. These results suggest that the SWDM method has a comparable level of applicability to gait EMG normalization as the isometric MVC method.

Dynamometer measurements of grip and knee extension strength: are they indicative of overall limb and trunk muscle strength?

Single dynamometric measures are sometimes used to characterize overall muscle strength. This study examined the legitimacy of that practice by assessing how dynamometer measures of grip and knee extension strength related to manual muscle-test grades of each upper and lower limb and of the trunk. Based on correlations and principal component analysis, grip dynamometry can be used to characterize upper limb strength but not lower limb strength; knee extension dynamometry can be used to characterize lower limb and trunk strength.

Cervical muscles strength testing: methods and clinical implications

BACKGROUND

Neck muscles are responsible for directing the head and for maintaining its posture. As a result, the muscular mechanical output is correspondingly moderate but not insignificant as evidenced by a positive therapeutic effect when reconditioning is indicated.

SPECIAL FEATURES

Cervical muscle strength (CS) measurement and interpretation occupy a unique niche in the domain of muscle performance. Due to the wide variety of devices and protocols, a vast range of strength scores has been reported, denying the formation of reliable reference values.

METHODS

A literature search based on the keywords "cervical/head/neck" strength was conducted. The search yielded 34 relevant papers which were reviewed according to preset criteria.

SUMMARY

Overall studies indicate that compared to normal subjects patients suffering from neck-related disorders present with significant reduction in CS, whereas women are weaker than men by about 40%. Noteworthy a significant drop in CS in both sexes is delayed until the seventh decade. In terms of its reproducibility, CS findings have been investigated using primarily relative parameters, and hence, the associated error is not yet established. Therefore, application of CS as a clinical outcome measure, particularly for assessing change due to intervention, should be critically conducted.

Strength measurements of the intrinsic hand muscles: a review of the development and evaluation of the Rotterdam intrinsic hand myometer

Numerous neurological diseases are accompanied by atrophy of the intrinsic muscles of the hand. Muscle strength testing of these muscles is frequently used for clinical decision making. Traditionally, these strength measurements have focused on manual muscle testing (MMT) or on grip and pinch strength dynamometry. We have developed a hand-held dynamometer, the Rotterdam Intrinsic Hand Myometer (RIHM), to measure this intrinsic muscle strength. The RIHM was designed such that it can measure a wide range of muscle groups, such as the abduction and adduction strength of the little finger and index finger, the opposition, palmar abduction (anteposition) and opposition strength of the thumb, and intrinsic muscles of the fingers combined in the intrinsic plus position. We found that the reliability of RIHM measurements in nerve injury patients was comparable to grip and pinch strength measurements and is appropriate to study the functional recovery of the intrinsic muscles of the hand in isolation. We have applied the RIHM in a recent study on the long-term outcome of muscle strength in patients with ulnar and median nerve injuries and found that while recovery of grip and pinch strength was relatively good, recovery of the ulnar nerve innervated muscles measured with the RIHM was poor. This poor recovery could not be detected with manual muscle strength testing or with grip and pinch dynamometry. We conclude that the RIHM provides an accurate clinical assessment of the muscle strength of the intrinsic hand muscles that adds valuable information to MMT and grip and pinch dynamometry.

Examination of the elbow: linking diagnosis, prognosis, and outcomes as a framework for maximizing therapy interventions

A conceptual framework for examination of the elbow by the therapist is presented. The role of history taking including patient life-style factors, comorbidities and goals; pain assessment; utility of provocative maneuvers and range of motion analysis are presented. Assessment of strength using hand-held dynamometry is described. Pain and disability measures relevant to patients with elbow pathology are discussed and one patient self report instruments is appended (the Patient-rated Elbow Evaluation). The psychometrics properties of tests for the elbow, when available, are reviewed. A template for recording an elbow examination is provided.

Median and ulnar neuropathies in university guitarists

STUDY DESIGN

Descriptive study.

OBJECTIVES

To determine the presence of median and ulnar neuropathies in both upper extremities of university guitarists.

BACKGROUND

Peripheral nerve entrapment syndromes of the upper extremities are well documented in musicians. Guitarists and plucked-string musicians are at risk for entrapment neuropathies in the upper extremities and are prone to mild neurologic deficits.

METHODS AND MEASURES

Twenty-four volunteer male and female guitarists (age range, 18-26 years) were recruited from the Belmont University School of Music and the Vanderbilt University Blair School of Music. Individuals were excluded if they were pregnant or had a history of recent upper extremity or neck injury. Subjects completed a history form, were interviewed, and underwent a physical examination. Nerve conduction status of the median and ulnar nerves of both upper extremities was obtained by performing motor, sensory, and F-wave (central) nerve conduction studies. Descriptive statistics of the nerve conduction study variables were computed using Microsoft Excel.

RESULTS

Six subjects had positive findings on provocative testing of the median and ulnar nerves. Otherwise, these guitarists had normal upper extremity neural and musculoskeletal function based on the history and physical examinations. When comparing the subjects' nerve conduction study values with a chart of normal nerve conduction studies values, 2 subjects had prolonged distal motor latencies (DMLs) of the left median nerve of 4.3 and 4.7 milliseconds (normal, < 4.2 milliseconds). Prolonged DMLs are compatible with median neuropathy at or distal to the wrist. Otherwise, all electrophysiological variables were within normal limits for motor, sensory, and F-wave (central) values. However, comparison studies of median and ulnar motor latencies in the same hand demonstrated prolonged differences of greater than 1.0 milliseconds that affected the median nerve in 2 additional subjects, and identified contralateral limb involvement in a subject with a prolonged distal latency. The other 20 subjects demonstrated normal comparison studies of the median and ulnar nerves in both upper extremities.

CONCLUSIONS

In this descriptive study of a population of 24 university guitarists, 4 musicians (17%) were found to have electrophysiologic evidence of median neuropathy at or distal to the wrist or carpal tunnel syndrome. Ulnar nerve electrophysiological function was within normal limits for all subjects examined.

Mesure de la force des muscles rotateurs de l'épaule chez des sportifs sains de haut niveau (natation, volley-ball, tennis) par dynamomètre isocinétique : comparaison entre épaule dominante et non dominante

OBJECTIVE

To compare lateral rotator (LR) and medial rotator (MR) muscle strength of both shoulders in a sport involving asymmetrical movements (tennis), symmetrical movements (swimming), and symmetrical and asymmetrical movements (volley-ball).

MATERIALS AND METHODS

Retrospective study of 42 healthy elite athletes (18 women: 14 tennis players, 19 swimmers and 9 volleyball players. We evaluated the strength of LR and MR of both shoulders by Cybex Norm isokinetic dynamometer, in the concentric mode, in the modified Davies position, at 2 different speeds (60 degrees and 180 degrees s(-1)) and analysed peak torque of LR and MR and LR/MR ratios.

RESULTS

TENNIS: The MR peak torque of the dominant shoulder was significantly higher than that of the non-dominant shoulder. The LR/MR ratio of the dominant shoulder was significantly lower than the non dominant shoulder in women. SWIMMING: The LR strength and LR/MR ratio of the dominant shoulder was higher than the non dominant side in men at 60 degrees/second. Both shoulders showed comparable strength in women. VOLLEYBALL: Shoulder muscular strength was symmetrical.

CONCLUSION

The higher strength of MR muscles in the dominant shoulder of tennis players (asymmetrical movements) has been reported in the literature. Athletes show asymmetrical shoulder strength in swimming, a symmetrical sport and similar LR and MR strength in both shoulders in volleyball, a sport with asymmetrical movements. To our knowledge, these results have never been reported before.