Upper Extremity Motor Fatigability as an Early Indicator in Pediatric Onset Multiple Sclerosis.

AIM: To adopt a computer-based protocol to assess grip fatigability in patients with pediatric-onset multiple sclerosis to provide detection of subtle motor involvement identifying those patients most at risk for future decline. METHOD: Pediatric-onset multiple sclerosis patients were recruited during routine outpatient visits to complete a grip assessment and compared to a group of healthy age- and sex-matched controls. All participants completed a computer-based measurement of standard maximal grip strength and repetitive and sustained grip performance measured by dynamic and static fatigue indices. RESULTS: A total of 38 patients with pediatric-onset multiple sclerosis and 24 healthy controls completed the grip protocol (right-hand dominant). There were no significant group differences in maximal grip strength bilaterally (right: 21.8 vs 19.9 kg, P = .25; left: 20.4 vs 18.7 kg, P = .33), although males with pediatric-onset multiple sclerosis were significantly less strong than healthy controls (right: 26.53 vs 21.23 kg, P = .009; left; 25.13 vs 19.63 kg, P = .003). Both dynamic and static fatigue indices were significantly higher bilaterally in pediatric-onset multiple sclerosis compared with healthy control participants (left-hand dynamic fatigue index: 18.6% vs 26.7%, P = .003; right-hand static fatigue index: 28.3% vs 41.3%, P < .001; left-hand static fatigue index: 31.9% vs 42.6%, P < .001). CONCLUSION: Brief repeatable grip assessment including measures of dynamic and sustained static output can be a sensitive indicator of upper extremity motor involvement in pediatric-onset multiple sclerosis, potentially identifying those in need of intervention to prevent future disability.

Comparison of clinical outcomes following early rehabilitation in 3 cases of nephrotic syndrome with different treatment courses.

There have been few published reports regarding rehabilitation for nephrotic syndrome. We compared the clinical outcomes of three cases of nephrotic syndrome with different treatment courses during 5 weeks of early rehabilitation.We report on three cases of nephrotic syndrome. Case 1 was a 67-year-old male who showed good progress after steroid treatment. Quadriceps torque and exercise capacity were increased after intervention. Case 2, a 78-year-old male, demonstrated resistance to steroid treatment. Quadriceps torque was decreased and exercise capacity was increased after intervention. Case 3 was an 83-year-old male who received nutrition therapy and diuretics without steroid treatment. Quadriceps torque and exercise capacity were decreased post-intervention.Early rehabilitation should be considered even if the steroid treatment course is different; furthermore, it is necessary to carefully consider the optimal exercise load in patients with nephrotic syndrome for whom regardless of whether or not steroid treatment is used.

The influence of maximum isometric muscle force scaling on estimated muscle forces from musculoskeletal models of children with cerebral palsy.

BACKGROUND: Musculoskeletal models do not include patient-specific muscle forces but rely on a scaled generic model, with muscle forces left unscaled in most cases. However, to use musculoskeletal simulations to inform clinical decision-making in children with cerebral palsy (CP), inclusion of subject-specific muscle forces is of utmost importance in order to represent each child's compensation mechanisms introduced through muscle weakness. RESEARCH AIM: The aims of this study were to (i) evaluate if maximum isometric muscle forces (MIMF) in musculoskeletal models of children with CP can be scaled based on strength measurements obtained with a hand-held-dynamometer (HHD), (ii) evaluate the impact of the HHD based scaling approach and previously published MIMF scaling methods on computed muscle forces during gait, and (iii) compare maximum muscle forces during gait between CP and typically developing (TD) children. METHODS: Strength and motion capture data of six CP and motion capture data of six TD children were collected. The HHD measurements to obtain hip, knee and ankle muscle strength were simulated in OpenSim and used to modify MIMF of the 2392-OpenSim model. These muscle forces were compared to the MIMF scaled on the child's body mass and a scaling approach, which included the body mass and muscle-tendon lengths. OpenSim was used to calculate peak muscle forces during gait. RESULTS: Ankle muscle strength was insufficient to reproduce joint moments during walking when MIMF were scaled based on HHD. During gait, peak hip and knee extensor muscle forces were higher and peak ankle dorsi-flexor forces were lower in CP compared to TD participants. SIGNIFICANCE: HHD measurements can be used to scale MIMF for the hip and knee muscle groups but underestimate the force capacity of the ankle muscle groups during walking. Muscle-tendon-length and mass based scaling methods affected muscle activations but had little influence on peak muscle forces during gait.

Grip strength cutpoints for youth based on a clinically relevant bone health outcome.

The National Academy of Medicine recommends the handgrip for school-based surveillance of muscle strength for bone health. We established grip strength cutpoints that are linked to bone health in both US and European youth. These cutpoints could serve as a potential set of standards for surveillance and clinical applications. PURPOSE: The U.S. National Academy of Medicine and experts in Europe recommend the use of grip strength as a valuable and accessible musculoskeletal fitness measure due to its association with bone health. This is the first study to facilitate this recommendation by developing bone health-related grip strength cutpoints for youth based on empirical associations with the well accepted marker of bone development, i.e., height-adjusted total body less head bone mineral content (TBLH_BMC). METHODS: A purposive sample of healthy youth from Midwest USA (n = 433 youth; 14.1 ± 2.3 years; 1998-2004) and a random sample of healthy adolescents from Zaragoza, Spain (n = 355 youth; 14.9 ± 1.2 years; 2006-2007) were used to develop and test cut-points. Participants' grip strength was measured using a hand-held dynamometer while height-adjusted TBLH_BMC was determined using dual-energy x-ray absorptiometry. Grip strength scores were linked to TBLH_BMC using receiver operator characteristic curves, and grip strength cutpoints were tested based on the area under the curve (AUC), sensitivity (Se), specificity (Sp), and predictive odds ratios. All analyses were conducted in 2016. RESULTS: The AUC approximated or exceeded 0.80 for grip strength cutpoints, and the associated Se and Sp indices ranged from 53.6 to 92.5%. Sensitivity and Sp remained similar in the validation sample and those not meeting the grip strength cutpoints were five to eight times more likely to have insufficient TBLH_BMC, depending on their sex and cutpoint being considered. CONCLUSIONS: Grip strength is strongly related to TBLH_BMC, and the proposed cutpoints demonstrated acceptable classification accuracy for screening healthy youth and tracking healthy bone development in community settings. The utility of the cutpoints should be further examined in more diverse populations of youth.

Validity and reliability of evaluating hip abductor strength using different normalization methods in a functional electromechanical device.

The hip abductor muscles are vitally important for pelvis stability, and common strength deficits can negatively affect functionality. The muscle strength can be measured using different dynamometers and be evaluated in three positions (side-lying, standing, and supine). Obtained strength data can be expressed in different ways, with data normalization providing more objective and comparable results. The aim of this study was to establish the validity and reliability of three protocols in evaluating the isometric strength of the hip abductor muscles. A new functional electromechanical dynamometer assessed strength in three positions, with findings subjected to three data normalization methods. In two identical sessions, the hip abductor strengths of 29 subjects were recorded in the side-lying, standing, and supine positions. Peak force was recorded in absolute terms and normalized against body mass, fat-free mass, and an allometric technique. The peak force recorded in the side-lying position was 30% and 27% higher than in the standing and supine positions, respectively, independent of data normalization methodology. High inter-protocol correlations were found (r: 0.72 to 0.98, p ≤ 0.001). The supine position with allometric data normalization had the highest test-retest reliability (0.94 intraclass correlation coefficient and 5.64% coefficient of variation). In contrast, the side-lying position with body mass data normalization had a 0.66 intraclass correlation coefficient and 9.8% coefficient of variation. In conclusion, the functional electromechanical dynamometer is a valid device for measuring isometric strength in the hip abductor muscles. The three assessed positions are reliable, although the supine position with allometric data normalization provided the best results.

Role of pain in measuring shoulder strength abduction and flexion with the Constant-Murley score.

OBJECTIVES: The Constant-Murley score (CS) has been used for more than 25 years to assess shoulder function. Strength by itself accounts for 25% of the total score. The measurement at 90° abduction seems to be sometimes limited by pain, particularly with tendinopathy or subacromial impingement. We compared the assessment of isometric strength in anterior forward flexion and abduction and its effect on pain and total CS. METHODS: Strength was assessed by CS at both 90° forward flexion and abduction in the scapular plane by using an Isobex dynamometer, the first position tested being randomized. Pain was assessed on a 100-mm visual analog scale (VAS) and total CS was assessed. RESULTS: We included 54 patients with unilateral shoulder problems; 50% had rotator cuff injury. Mean strength on the affected side was 4.7±2.5kg in forward flexion and 4.6±2.8kg in abduction. Induced pain and total CS did not differ between the 2 positions tested. CONCLUSIONS: Strength can be measured by the CS in forward flexion or abduction, because the measurement does not affect strength, pain intensity or total score. The choice of direction for measurement should be based on the underlying pathology, related contraindications and patient preference.

Validity analysis of one-repetition maximum strength test for determining the hamstrings-to-quadriceps ratio

One of the approaches to evaluate injury prediction is the hamstrings-to-quadriceps peak torque conventional ratio (H:Q ratio). The gold standard for assessment of muscle strength in vivo is by isokinetic dynamometry; however, the one-repetition maximum strength test (1-RM) presents high correlation with isokinetic data. This study aimed to compare measures of H:Q ratio in young adults obtained by dynamometry and 1-RM testing. No significant differences were observed in the H:Q ratio when comparing 1-RM and dynamometry testing. However, there was a significant and strong correlation between the measurements obtained in the two tests. Despite this correlation, data from both tests are not equal as the H:Q ratio obtained from 1-RM test presents a systematic error. Nonetheless, the results can enhance the applicability of 1-RM test in clinical settings

Using handgrip strength to screen for diabetes in developing countries.

Lack of access to healthcare in the developing world has created a need for locally-based primary and pre-primary healthcare systems. Many regions of the world have adopted Community Health Worker (CHW) programmes, but volunteers in these programmes lack the tools and resources to screen for disease. Because of its simplicity of operation, handgrip strength (HGS) measurements have the potential to be an affordable and effective screening tool for conditions that cause muscle weakness in this context. In the study described in this report, translators were used to collect data on age, gender, height, weight, blood pressure, HGS and key demographic data. HGS was significantly lower for diabetics than patients without diabetes. A simple binary logistic model was created that used HGS, age, blood pressure and BMI to predict a patient's probability of having diabetes. This study develops a predictive model for diabetes using HGS and other basic health measurements and shows that HGS-based screening is a viable method of early detection of diabetes.

Fatores associados à força de preensão manual diminuída em idosos / Factors associated with decreased hand grip strength in the elderly

Objetivo: Investigar os fatores associados à diminuição da Força de Preensão Manual (FPM) em idosos. Métodos: Estudo quantitativo transversal, cuja amostra foi constituída por 203 idosos da atenção primária à saúde. Os dados foram coletados entre janeiro e abril de 2013 mediante questionário sociodemográfico/clínico e teste de FPM. Aplicou-se estatística descritiva e teste qui-quadrado, considerados significativos os valores de p ≤ 0,05. Resultados: 48,8% dos idosos apresentaram FPM diminuída, associada às variáveis sexo (p < 0,001), idade (p < 0,012), estado civil (p < 0,005), escolaridade (p < 0,027), quedas (p < 0,001) e tecnologias assistivas (p < 0,024). Conclusão: Foi elevada a distribuição da FPM diminuída, isso é preocupante, uma vez que é um fator limitante para as atividades de vida diária. A associação significativa entre algumas variáveis reforçam essas restrições. Investigar os fatores associados à diminuição da FPM instrumentaliza os enfermeiros para a gestão da fragilidade e ela poderá evitar desfechos para a síndrome da fragilidade física.

Peripheral muscle strength and correlates of muscle weakness in patients receiving mechanical ventilation.

BACKGROUND: Intensive care unit-acquired weakness is a frequent complication of critical illness because of patients' immobility and prolonged use of mechanical ventilation. OBJECTIVES: To describe daily measurements of peripheral muscle strength in patients receiving mechanical ventilation and explore relationships among factors that influence intensive care unit-acquired weakness. METHODS: Peripheral muscle strength of 120 critically ill patients receiving mechanical ventilation was measured daily by using a standardized handgrip dynamometry protocol. Three grip measurements for each hand were recorded in pounds-force; the mean of these 3 assessments was used in the analysis. Correlates of intensive care unit-acquired weakness (age, sex, illness severity, duration of mechanical ventilation, medications) were analyzed by using mixed models to explore the relationship to grip strength. RESULTS: Median baseline grip strength was variable yet diminished (7.7 pounds-force), with either a pattern of diminishing grip strength or maintenance of the baseline low grip strength over time. With controls for days of measurement, female sex (ß = -10.4; P < .001), age (ß = -0.24; P = .004), and days receiving mechanical ventilation (ß = -0.34; P = .005) explained a significant amount of variance in grip strength over time. CONCLUSIONS: Patients receiving prolonged mechanical ventilation had marked decrements in grip strength, measured by hand dynamometry, a marker for peripheral muscle strength. Hand dynamometry is a reliable method for measuring muscle strength in cooperative critically ill patients and can be used to develop interventions to prevent intensive care unit-acquired weakness.

Determination the validity of the new developed Sport Experts® hand grip dynamometer, measuring continuity of force, and comparison with current Takei and Baseline® dynamometers.

AIM: In this study the Sport Experts ™ brand of hand grip dynamometer, measuring the continuity of force with the new developed load cell technology, was compared with Takei and Baseline® dynamometers, the current in use. It was tried to determine the correlation between them. In a study with provides use of clinical, orthopedic and rehabilitative purposes in the athletes and patient populations, this developed dynamometer can provide useful data by observing the continuity of force. METHODS: The sample of the study included 60 badminton players in 2010-2011; consisting of Turkish Junior National male players (N.=16, age: 16.8±1.5), Junior National female players (N.=14, age: 16.9±1.6), amateur level male players (N.=15, age: 16.3±0.8) and amateur level female players (N.=15, age: 16.1±0.6). ANOVA was used in the statistical methods in order to compare the hand grip strength made by different brands; Pearson's correlation coefficient was used to determine the relationship level between dynamometers. Furthermore, test-retest reliability analysis was completed the new developed expert dynamometer. RESULTS: There was no statistically significant difference in the comparison of the dynamometers (P>0.05). Besides, a highly significant relationship (r=0.95 to 0.96) was found among all three dynamometers. However, the reliability coefficient was found (Chronbachs α: 0.989, ICC:0.97, r=0.97), (P<0.01) for the new developed expert dynamometer. CONCLUSION: Comparison between the dynamometers and the statistical results obtained from the correlation relationships shows interchangeability of dynamometers. As a result, our observation of force continuity (progression) of the athlete and patient populations is thought to be important.

Tongue pressure as a novel biomarker of spinal and bulbar muscular atrophy.

OBJECTIVE: This study aimed to explore the reliability and validity of tongue pressure measurement as a quantitative evaluation of swallowing function in patients with spinal and bulbar muscular atrophy (SBMA). METHODS: This study enrolled 47 genetically confirmed patients with SBMA and 38 age- and sex-matched healthy controls. In both groups we measured tongue pressure using an intraoral pressure probe and assessed questionnaires that evaluated swallowing functions. We then analyzed the relationship between tongue pressure, functional scales, and the muscle weakness of other regions. RESULTS: Levels of tongue pressure were decreased in patients with SBMA within 3 years from the onset of the disease compared to healthy controls (SBMA 15.3 ± 6.4 kPa; healthy controls 37.3 ± 9.6 kPa; p < 0.001). Test-retest analysis showed a high reliability in patients with SBMA (intraclass correlation coefficient = 0.986). Tongue pressure showed a strong correlation with bulbar-related functional scales. Decrease of tongue pressure was detected in patients who reported no subjective dysphagia, and repetition of swallowing compensated for tongue weakness in such subjects. In patients with SBMA, tongue pressure more strongly correlates with the strength of pharyngeal, neck, and upper limb musculatures than with that of the lower limbs. CONCLUSION: Tongue pressure measurement is reliable and reflects swallowing function in patients with SBMA. The muscle strength of the tongue appears to decrease in SBMA before the awareness of subjective dysphagia, suggesting that tongue pressure measurement is a novel biomarker of SBMA and is applicable to early-stage detection.

Test-retest reliability of innovated strength tests for hip muscles.

The burden of hip muscles weakness and its relation to other impairments has been well documented. It is therefore a pre-requisite to have a reliable method for clinical assessment of hip muscles function allowing the design and implementation of a proper strengthening program. Motor-driven dynamometry has been widely accepted as the gold-standard for lower limb muscle strength assessment but is mainly related to the knee joint. Studies focusing on the hip joint are less exhaustive and somewhat discrepant with regard to optimal participants position, consequently influencing outcome measures. Thus, we aimed to develop a standardized test setup for the assessment of hip muscles strength, i.e. flexors/extensors and abductors/adductors, with improved participant stability and to define its psychometric characteristics. Eighteen participants performed unilateral isokinetic and isometric contractions of the hip muscles in the sagittal and coronal plane at two separate occasions. Peak torque and normalized peak torque were measured for each contraction. Relative and absolute measures of reliability were calculated using the intraclass correlation coefficient and standard error of measurement, respectively. Results from this study revealed higher levels of between-day reliability of isokinetic/isometric hip abduction/flexion peak torque compared to existing literature. The least reliable measures were found for hip extension and adduction, which could be explained by a less efficient stabilization technique. Our study additionally provided a first set of reference normalized data which can be used in future research.

The effects of an exercise training program on hand and wrist strength, and function, and activities of daily living, in adults with severe cerebral palsy.

The purpose of the current study was to establish measurement reliability in adults with Cerebral Palsy (CP), and to examine the feasibility and outcomes of an upper extremity strength training program (three times per week for 90 min each time). A control group design mixed with a prospective time series design for the intervention group was completed, including a pre-test, a post-test after a 12-week intervention period, and a follow-up in the intervention group after an additional 10-week period. Seventeen adults with CP with severe motor impairment took part in the study (10 in the intervention and seven in the control group). The test battery was comprised of wrist and hand dynamometry; dominant hand upper-extremity function measures (Jebsen Hand Function Test=JHFT, Minnesota Manual Dexterity Test=MMDT, and the Nine Hole Peg Test=NHPT); and activity of daily living with the Barthel Index. The results indicated that in both the control and the intervention groups, the strength tests exhibited good-to-excellent reliability during pre-test and post-test. The group comparison revealed that while in the pre-test no between-group differences existed, in the post-test the strength training group demonstrated significantly higher values in five out of eight strength measures, as well as in the MMDT. Discontinuing the program for eight weeks reversed the effects almost to baseline. In conclusion, the outcomes demonstrated the reliability of the assessments utilized in this study, as well as the feasibility of the strength training program, in adults with severe motor impairment due to CP.

Hip strength assessment using handheld dynamometry is subject to intertester bias when testers are of different sex and strength.

Handheld dynamometry (HHD) is a promising tool for obtaining reliable hip strength measurements in the clinical setting, but intertester reliability has been questioned, especially in situations where testers exhibit differences in upper-extremity muscle strength (male vs female). The purpose of this study was to examine the intertester reliability concerning strength assessments of hip abduction, adduction, external and internal rotation, flexion and extension using HHD, and to test whether systematic differences in test values exist between testers of different upper-extremity strength. Fifty healthy individuals (29 women), aged 25 ± 5 years were included. Two physiotherapist students (one female, one male) of different upper-extremity strength performed the measurements. The tester order and strength test order were randomized. Intraclass correlation coefficients were used to quantify reliability, and ranged from 0.82 to 0.91 for the six strength test. The female tester systematically measured lower strength values for all isometric strength tests (P < 0.05). In hip strength assessments using HHD, systematic bias exists between testers of different sex, which is likely explained by differences in upper-extremity strength. Hence, to improve intertester reliability, the dynamometer likely needs external fixation, as this will eliminate the influence of differences in upper-extremity strength between testers.

Test-retest reliability of computerised hand dynamometry in adults with acquired brain injury.

BACKGROUND/AIM: The ability to objectively and reliably measure hand performance over time is critical to monitor patient performance and evaluate treatment efficacy. Current spasticity measures are subjective in nature and fail to capture the complexity of the multi-faceted upper motor neuron syndrome. This study examined the test-retest reliability of dynamic computerised hand dynamometry for simultaneously measuring multiple aspects of positive and negative features of the upper motor neuron syndrome during an active grasp and release task. METHODS: Community-living adults with upper motor neuron syndrome following acquired brain injury attending metropolitan spasticity clinics for management of upper limb spasticity (N = 36; mean age 50 years ±15) and control participants (N = 27, mean age 40 years ±12) completed a computerised hand dynamometry protocol across two testing occasions 5 weeks apart. Objective measurement of Isometric Force, Cycle Duration and Isometric Grip Work, Force Velocity, was completed during a repeated grasp and release test protocol with a computerised hand dynamometer to evaluate the reliability and reproducibility of hand performance. RESULTS: Kendall Coefficient of Concordance W scores ranged from W = 0.69-0.98 for motor elements of grasp and release, including Isometric Force, Cycle Duration, Isometric Grip Work and Force Velocity. CONCLUSIONS: The investigated dynamic computerised hand dynamometry protocol showed fair/good to excellent levels of test-retest reliability in control participants and in subjects with upper motor neuron syndrome following acquired brain injury.

Physical effect of work on healthy individuals: implications for FCE testing.

OBJECTIVE: The objective of this study was to assess the effect of time of day and job type on performance of three functional capacity evaluation measures in healthy (asymptomatic) adults. It was queried whether or not a healthy population of adults would demonstrate a change in physical performance ability, when re-tested at the end of their work day. SETTING: A convenience sample of 50 healthy adults (19-62 years, 66% male) was used from six work sites in an urban area. DESIGN: Same day pre-test and post-test testing was performed, implementing use of three commonly used functional capacity tests: Jamar dynamometer grip strength test, Turning sub-test of the Complete Minnesota Dexterity Test, and the 50-foot walk test. METHODS: The study compared morning and afternoon test scores, and using t-tests, assessed the effect of job type (sedentary, light, medium, heavy) on performance using ANOVA. RESULTS: All three measures improved from morning to afternoon; differences were statistically significant for 50-foot walk (mean=0.2 sec, p=0.02) and manual dexterity (mean=5 sec, p< 0.001). Job type had a significant effect on dexterity. CONCLUSIONS: Late day performance did not show any significant decline in this sample of healthy adults, and in fact tended to improve or stay relatively stable. Therefore, clinicians who perform functional capacity evaluations should consider alternative explanations for late-day functional declines observed in injured patients. These findings, combined with other test results, may assist clinicians with disability determination.

Age and sex differences of controlled force exertion measured by a computer-generated quasi-random target-pursuit system.

OBJECTIVES: This study examined age and sex differences of controlled force exertion measured by a computer-generated quasi-random target-pursuit system in 207 males and 249 females aged 15 to 86 years. METHODS: The participants matched submaximal grip exertion of their dominant hand to changing demand values, appearing as a moving quasi-random waveform on the display of a personal computer. They performed the test three times with 1-min intervals (one trial was 40 sec). The total sum of the percent of differences between the demand value and the grip exertion value for 25 sec was used as an evaluation parameter. RESULTS: The errors in controlled force exertion tended to increase constantly with age in both sexes. Significant linear regressions were identified, but there was no significant difference in the rate of increase in both sexes. Analysis of variance showed nonsignificant sex differences among means, except for those in individuals older than 60 years; significant differences between means in the groups older than the 40 yr.-old age group and the 20-24 yr.-old group were found in both sexes. CONCLUSIONS: Controlled force exertion did not show a significant sex difference and decreased gradually with age in both sexes, but decreased remarkably after 40 years of age.