Reference Values For Strength Research Articles

Weight-Specific Grip Strength as a Novel Indicator Associated with Cardiometabolic Risk in Children: The EMSNGS Study.

Handgrip strength (HGS) is an important indicator of sarcopenia and adverse health outcomes. However, evaluating HGS in children presents challenges, and its association with metabolism remains incompletely understood. To establish grip strength reference values for Chinese children and adolescents, as well as to evaluate the relationship between HGS and cardiometabolic risk. Data were collected from 4 072 participants aged 6-18 as part of the Evaluation and Monitoring on School-based Nutrition and Growth in Shenzhen (EMSNGS) study. HGS was measured, and relative HGS (RHGS) was normalized by body mass index. Age- or weight-specific HGS and RHGS were derived using the generalized additive model of location, scale, and shape (GAMLSS) model, and participants' values were categorized into quartiles, defining low strength as the lowest quartile. The cardiometabolic risk index (CMRI) z-score was calculated, with high risk defined as a z-score of ≥ 1. Both boys and girls exhibited similar increases in age- and weight-specific grip strength. Low grip strength, classified by weight-specific HGS and RHGS, was linked to higher CMRI z-scores compared to classifications based on age-specific references in both sexes. A dose-dependent relationship was observed between weight-specific grip strength and cardiometabolic risk, particularly in boys. Compared to the middle category (P25th-P75th), the odds ratios for high cardiometabolic risks associated with low grip strength increased in both sexes. This study established grip strength reference values for Chinese youth, introduced the concept of weight-specific HGS and RHGS, and demonstrated a dose-dependent relationship between weight-specific grip strength and cardiometabolic risk. These findings highlighted the association between low muscle strength and increased cardiometabolic risk.

Establishment of regression-based isometric strength reference values for the upper limb in persons with multiple sclerosis.

Muscle weakness is common and significantly affects persons with multiple sclerosis (PwMS), with dysfunction in upper limb (UL) muscle groups occurring in approximately 60% of PwMS. To develop gender-specific regression-based prediction equations, with 95% confidence intervals for maximal bilateral UL isometric strength (shoulder abduction and adduction, wrist flexion and extension) and hand grip strength in PwMS. Cross-sectional study. Comprehensive MS center. 256 PwMS. Not Applicable. Shoulder abduction and adduction and wrist flexion and extension isometric strength(Biodex System 4 Pro Dynamometer) and hand grip strength (Jamar handheld dynamometer) were measured. Disease characteristics (disability and disease duration) and demographics (age, height, and weight) were collected. Regression-based predictive equations were generated for the UL muscle groups for each gender and limb, using age, height, weight, disability, and disease duration as covariates. Variables were compared between genders using the Mann-Whitney U test. Maximal voluntary contraction (MVC) reference values (mean ± SD) were reported based on age (<30, 30-39, 40-49, 50-59, 60-69 years) and disability (mild, moderate, severe ambulant, and severe nonambulant) for each gender and limb. Regression-based equations were developed for both genders' strongest and weakest limb, accounting for age, height, weight, disability, and disease duration. MVC was higher in men than women (p < .001) in all muscle groups. Overall, MVC was significantly related to age in 14, height in 5, weight in 6, disability in 14, and disease duration in none of the 20 models. This is the first study to provide regression-based prediction equations for strongest and weakest MVC of UL muscle groups and demonstrated an inverse relationship between MVC with disability and age. Regression-based reference strength values can help clinicians understand muscular strength along a spectrum of PwMS and can aid in goal setting and education for realistic outcomes.

Hip adduction and abduction strength in youth male soccer and basketball players with and without groin pain in the past year.

The objectives of this study were to 1) assess the differences between youth soccer and basketball players with and without past year groin pain (GP) in hip adduction and abduction strength and several training characteristics (age at the start of regular training, weekly training frequency, warm-up and training duration, use of stretching and/or stabilisation exercises during warm-up, use of resistance training); 2) present strength reference values for youth soccer and basketball players. 227 players participated (age 16.9 ± 1.4 years; height 184.2 ± 8.5 cm; mass 75.5 ± 11.9 kg). Hip adduction and abduction strength was measured in supine position (hip, knee and ankle in neutral position) using a MuscleBoard dynamometer. Interlimb asymmetries and hip adduction:abduction ratios were calculated. Past year GP and training characteristics were assessed with a retrospective questionnaire. 11.9% of players reported past year GP (16.9% in soccer and 6.4% in basketball). The only significant difference between the past year GP and the control groups was found in the age of the players at the start of regular training (7.2 ± 1.8 years for the GP group vs. 8.5 ± 2.6 years for the control group). Additionally, soccer players without past year GP have significantly higher hip adduction strength (1.1 ± 0.2 Nm/kg vs. 1.0 ± 0.2 Nm/kg) and adduction:abduction strength ratio (1.10 ± 0.18 vs. 1.03 ± 0.16) compared to basketball players. Our results show that hip adduction and abduction strength, interlimb asymmetry and hip adduction:abduction ratio do not differentiate between players with and without past year GP (p = 0.29–0.90), which means that their adduction or abduction strength can be analysed regardless of the GP presence in the past year. Additionally, players with past year GP started regularly training at significantly lower age, which could indicate the problematic nature of early/premature sports specialisation.

Muscle Strength Reference Values and Correlation with Appendicular Muscle Mass in Mexican Children and Adolescents.

Strength and muscle mass are important determinants of health status, and reference values for pediatric populations from every country or geographic region are needed. The aim of this study was to develop age- and sex-specific reference values of muscle strength and evaluate the correlation between muscle strength and appendicular lean mass in Mexican children and adolescents. A cross-sectional study was conducted in 1111 healthy subjects ages 5 to 19years of age participating in the "Body Composition Reference Values in Mexican Children and Adolescents" study. Smoothed reference values for the 1, 3, 5, 15, 25, 50, 75, 85, 95, 97, and 99 percentiles of muscle strength for upper and lower limbs were developed based on age and sex using Jamar® and Microfet2® dynamometers. Mean values were derived using the Generalized Additive Models for Location, Scale and Shape (GAMLSS), and lean mass was determined using dual-energy X-ray absorptiometry. Highly positive correlations of muscle strength with lean mass in upper limbs were found r-values 0.87-0.92 for boys and r = 0.80-0.86 for girls. High and moderate positive correlations for lower limbs were also noted for upper limbs: r = 0.74-0.86 for boys and r = 0.67-0.82 for girls. The reference values for appendicular muscle strength established in this study demonstrated a high and positive correlation between appendicular mass and muscle strength. These data will be useful when evaluating conditions and diseases affecting muscle or sports.

Lower extremity muscle strength reference values for young Saudi male adults aged 21 to 23 years and their correlation with anthropometric parameters and balance

Normative reference values for muscle strength are needed for muscle strength assessment and estimation of prognosis in lower extremity related neuromuscular disorders, as muscle strength influenced by anthropometric parameters and muscle strength itself affects balance. Normative reference values for muscle strength in the Saudi Arabian population is lacking in the literature. Hence, the current study aimed to establish normative reference values for lower extremity muscle strength and to correlate these values with anthropometric parameters and balance. Lower extremity muscle strength and balance were assessed by baseline hand-held dynamometer and by forward, lateral, and oblique direction reach tests in 421 young male adults between 21 and 23 years of age. The mean and standard deviation of lower extremity strength ranged from 43.83 ± 16.92 lb to 62.07 ± 10.74 lb. Body weight, body mass index, and oblique and lateral reach distances were correlated with some knee and ankle muscle strength values. Body weight, body mass index, and balance showed significant effect on lower extremity muscle strength. Furthermore, decreased muscle strength may impair balance; the current clinical practice should evaluate body weight, body mass index, and muscle strength during the assessment process.

Quadriceps and Hamstrings Strength Reference Values for Athletes With and Without Anterior Cruciate Ligament Reconstruction Who Play Popular Pivoting Sports, Including Soccer, Basketball, and Handball: A Scoping Review.

To synthesize and present reference values for quadriceps and hamstrings strength tests in healthy athletes who play pivoting sports and in athletes with anterior cruciate ligament reconstruction (ACLR) who play pivoting sports. Scoping review. We searched PubMed, the Cochrane Library, MEDLINE, Embase, and Web of Science up to January 26, 2021. We included reference values in 2 different categories: (1) quadriceps and hamstrings strength test outcomes in healthy pivoting-sport athletes, and (2) quadriceps and hamstrings strength test outcomes in pivoting-sport athletes with ACLR at a specific time point during rehabilitation. We performed a qualitative synthesis for reference values from isokinetic (at 60°/s, 180°/s, and 300°/s) and isometric quadriceps and hamstrings strength tests. We summarized the data for type of sport, sex, sport participation level, and age group. Of the 42 included studies, 26 reported reference values from healthy soccer players, 4 from healthy basketball players, 4 from healthy handball players, and 11 from other healthy pivoting-sport athletes. The limb symmetry index dominant/nondominant limb (LSI-D/ND) ranged from 98% to 114% for healthy athletes. Six studies reported reference values in pivoting-sport athletes with ACLR at a specific time point during rehabilitation. After 7 months, strength values for athletes with ACLR were comparable to those of healthy pivoting-sport athletes. This scoping review summarizes quadriceps and hamstrings strength reference values for athletes who play the most common pivoting sports, including soccer, basketball, and handball. J Orthop Sports Phys Ther 2022;52(3):142-155. Epub 31 Dec 2021. doi:10.2519/jospt.2022.10693.

Prevalence of sarcopenia and its associated factors: the impact of muscle mass, gait speed, and handgrip strength reference values on reported frequencies

OBJECTIVES:Sarcopenia is a common treatable geriatric condition. The aim of this study was to estimate the prevalence of sarcopenia and its associated factors in community-dwelling elderly living in Rio de Janeiro, Brazil, and to discuss the impact of different muscle mass, handgrip strength and gait speed cut-off values on the reported frequency of sarcopenia.METHODS:The health habits, functional capacity, and anthropometric measurements of 745 individuals aged ≥65 years from the Frailty in Brazilian Older People study were analyzed. The participants were classified into the following four groups: no sarcopenia, pre-sarcopenia, sarcopenia and severe sarcopenia. Univariate and multivariate regression analyses were performed. Muscle mass, handgrip strength and gait speed cut-off thresholds tailored to the sample and those proposed by the European Working Group on Sarcopenia in Older People were used to compare the prevalence rates of sarcopenia.RESULTS:Seventy-three percent of the participants were female, 61.9% were Caucasian, and the mean age was 76.6 years. The prevalence rates of sarcopenia were 10.8% and 18% using the sample-tailored and European consensus cut-off values, respectively. Sarcopenia was associated with advanced age (OR: 37.2; CI95%12.35-112.48), Caucasian race (OR: 1.89; CI 95% 1.02-3.52), single marital status (OR:6; CI95% 2.2-16.39), low income (OR:3.64; CI 95% 1.58-8.39), and the presence of comorbidities (OR:3.26; CI 95%1.28-8.3).CONCLUSION:In this study, the estimated prevalence of sarcopenia was similar to that reported in most studies after the tailored handgrip strength and gait speed cut-off values were adopted. A higher prevalence was observed when the cut-off values suggested by the European consensus were used. This indicates that the prevalence of sarcopenia must be estimated using population-specific reference values.

Assessment and Comparison of Isokinetic Strength of Hip, Knee and Ankle Joints in Young Adults

This study was conducted to observe the isokinetic strength (IS) of the hip, ankle, and knee joints in young age groups. Thirty eight men and thirty one women with mean age of 30.4 ± 3.5 and 32.8 ± 4.4 years, respectively, were enrolled in this study. Measurements of hip flexion, extension, abduction, and adduction at 30° / sec, Knee flexion and extension at 60° / sec, ankle inversion, eversion, plantarflexion, and dorsiflexion 30° / sec were conducted. Absolute IS (Nm), relative IS (Nm/kg), strength ratios, correlations between movements were observed. Significant differences in absolute and relative strength were observed between groups in all movement except in the relative ankle strength. Relative isokinetic strength ratios of hip flexion/extension were .45 and .55, knee flexion/extension were .84 and .89, ankle dorsi/plantarflexion were .30 and .29, and ankle eversion/inversion were .86 and .84 for men and women, respectively. In the hip extension, men had about three times the body weight ,and women had about 2.5 times the strength. The abduction muscle had about 1.5 times the body weight of both men and women. Height and body weight showed the significantly strong correlating relationship with hip (r, .76-.86) and knee (r, .67-.84) strength. However, ankle strength showed the comparatively correlating relationship, especially in women (r, .03 - .36). Similar age and physique characteristics of female and male groups could provide useful isokinetic strength reference values for developing the exercise program for healthy and rehabilitation groups.

A Comparison of Hand Grip Strength between NHANES vs NIH Toolbox Studies

To provide and compare grip strength reference values obtained from two population-based studies: the National Health and Nutrition Examination Survey (NHANES) and the National Institutes of Health (NIH) Toolbox.

Handgrip strength values of Portuguese older adults: a population based study

BackgroundHandgrip strength is used to identify sarcopenia and frailty phenotypes, being a potential predictor of mortality in older adults. However, uniformity is lacking in the reference values. This study aimed to describe handgrip strength values of older population aged ≥65 years in Portugal, considering the possible influence of anthropometric parameters.MethodsA cross-sectional study was conducted in Portugal, among 1500 older adults aged ≥65 years old, according to “The Nutrition UP 65 Study Protocol”. Demographic data were collected and cognitive performance, subjective general health, physical activity, anthropometric parameters and nutritional status were assessed and analysed. Handgrip strength data was obtained with a Jamar dynamometer. A Pubmed/Medline search was carried out to compare handgrip strength data between Portuguese older adults and other older populations.ResultsHandgrip strength was higher among men than among women (30.3 ± 9.2 Kgf vs 18 ± 5.4 Kgf, p < 0.001, respectively). In general, handgrip strength values of Portuguese older adults were lower than other older populations. In our sample, age, cognitive and nutritional status, self-reported sitting time and practice of physical activity were significantly correlated with handgrip strength in both sexes. Concerning anthropometric parameters, height was the most significantly correlated with handgrip strength (r = 0.34, p < 0.001, in women and r = 0.40, p < 0.001, in men).ConclusionThis study described, for the first time, handgrip strength values of Portuguese population aged ≥65 years, according to age and to sex-specific tertiles of height. The definition of handgrip strength reference values in this age group merits further reflection.

Normative Values of Y Balance Test and Isometric Muscle Strength among Saudi School Children

Abstract Background To establish children-specific reference values for the Y-balance test (YBT) and Isometric muscle strength in school children of Saudi Arabia and to elucidate the relationship between YBT performance and lower limb muscle strength. Materials &amp; Methods Healthy School children (51 males) aged 12–15 years volunteered to participate in this study. Participants completed the YBT and maximal isometric muscle strength testing for knee extensors and flexors in a single testing session. Descriptive statistics were used to compute the YBT and muscle strength reference values. Paired t-tests were used to examine interlimb differences. Pearson’s correlation coefficient was used to quantify the linear relationships between YBT distances and lower limb strength. Results Tabulated children-specific reference values were presented for the right, left, dominant and non-dominant limbs. Participants exhibited longer distance in the posteromedial direction standing on the right (p=0.04), stronger knee extensors (p=0.03) on the dominant side and stronger knee flexors in the right side (p=0.01) and in the dominant side (p=0.01). Knee flexors muscle strength was positively related to the reach distances of the YBT in both the right and the left lower extremity (P&lt;0.05). Conclusion The current study provided the reference value for the YBT and muscle strength for the knee extensors and flexors in male children in Saudi Arabia. The interlimb difference in YBT performance was noted in only the posteromedial direction and the dominant side had stronger knee flexors and extensors. Muscle strength of the knee flexors was positively related to the reach distance in the YBT.

Normative reference values for strength and flexibility of 1,000 children and adults.

To establish reference values for isometric strength of 12 muscle groups and flexibility of 13 joint movements in 1,000 children and adults and investigate the influence of demographic and anthropometric factors. A standardized reliable protocol of hand-held and fixed dynamometry for isometric strength of ankle, knee, hip, elbow, and shoulder musculature as well as goniometry for flexibility of the ankle, knee, hip, elbow, shoulder, and cervical spine was performed in an observational study investigating 1,000 healthy male and female participants aged 3-101 years. Correlation and multiple regression analyses were performed to identify factors independently associated with strength and flexibility of children, adolescents, adults, and older adults. Normative reference values of 25 strength and flexibility measures were generated. Strong linear correlations between age and strength were identified in the first 2 decades of life. Muscle strength significantly decreased with age in older adults. Regression modeling identified increasing height as the most significant predictor of strength in children, higher body mass in adolescents, and male sex in adults and older adults. Joint flexibility gradually decreased with age, with little sex difference. Waist circumference was a significant predictor of variability in joint flexibility in adolescents, adults, and older adults. Reference values and associated age- and sex-stratified z scores generated from this study can be used to determine the presence and extent of impairments associated with neuromuscular and other neurologic disorders, monitor disease progression over time in natural history studies, and evaluate the effect of new treatments in clinical trials.

Maximal isometric muscle strength values obtained By hand-held dynamometry in children between 6 and 15 years of age.

In this study we aimed to determine the maximal isometric muscle strength of a healthy, normal-weight, pediatric population between 6 and 15 years of age using hand-held dynamometry to establish strength reference values. The secondary objective was determining the relationship between strength and anthropometric parameters. Four hundred normal-weight Chilean children, split into 10 age groups, separated by 1-year intervals, were evaluated. Each age group included between 35 and 55 children. The strength values increased with increasing age and weight, with a correlation of 0.83 for age and 0.82 for weight. The results were similar to those reported in previous studies regarding the relationships among strength, age, and anthropometric parameters, but the reported strength differed. These results provide normal strength parameters for healthy and normal-weight Chilean children between 6 and 15 years of age and highlight the relevance of ethnicity in defining reference values for muscle strength in a pediatric population. Muscle Nerve 55: 16-22, 2017.

Adherence to a standardized protocol for measuring grip strength and appropriate cut-off values in adults over 65 years with sarcopenia: a systematic review protocol.

REVIEW QUESTION / OBJECTIVE The objective of this review is to examine the use of grip strength analysis in well and unwell populations in adults 65 years and over as a tool to establish muscle strength in sarcopenia. More specifically, the main review question is: What protocol, if any, is most commonly used among older adults with sarcopenia and does this match the standardized protocol suggested in 2011 by Roberts et al.? Secondary review questions are: What are the reported cut-off values being used to determine sarcopenia in older adults, with consideration for ethnic and gender variability? Is grip strength, as a tool to measure muscle strength, suitable for people with common comorbidities and geriatric syndromes, such as osteoarthritis, often associated with sarcopenia? INCLUSION CRITERIA Types of participants Participants will be adults, aged 65 years and over living at home or in health or social care settings with sarcopenia as a prevailing pathology. The setting and whether the participants fulfil specific inclusion criteria or form part of an inclusive screening study will be recorded. Notes will be made for sarcopenia status, comorbidities, gender, ethnicity and other geriatric disorders. Studies across varied diseases and disabilities, including stroke, and musculoskeletal, neuromuscular and cognitive disease will be included in the interest of evaluating the suitability of hand grip assessment in these populations, with reference to the ability to complete protocol, free from pain or other relevant noted issues. While no specific exclusion criteria exist for this review, a comment on TRUNCATED AT 250 WORDS

Normal reference values of strength in pelvic floor muscle of women: a descriptive and inferential study.

BackgroundTo describe the clinical, functional and quality of life characteristics in women with Stress Urinary Incontinence (SUI). In addition, to analyse the relationship between the variables reported by the patients and those informed by the clinicians, and the relationship between instrumented variables and the manual pelvic floor strength assessment.MethodsTwo hundred and eighteen women participated in this observational, analytical study. An interview about Urinary Incontinence and the quality of life questionnaires (EuroQoL-5D and SF-12) were developed as outcomes reported by the patients. Manual muscle testing and perineometry as outcomes informed by the clinician were assessed. Descriptive and correlation analysis were carried out.ResultsThe average age of the subjects was (39.93 ± 12.27 years), (24.49 ± 3.54 BMI). The strength evaluated by manual testing of the right levator ani muscles was 7.79 ± 2.88, the strength of left levator ani muscles was 7.51 ± 2.91 and the strength assessed with the perineometer was 7.64 ± 2.55. A positive correlation was found between manual muscle testing and perineometry of the pelvic floor muscles (p < .001). No correlation was found between outcomes of quality of life reported by the patients and outcomes of functional capacity informed by the physiotherapist.ConclusionA stratification of the strength of pelvic floor muscles in a normal distribution of a large sample of women with SUI was done, which provided the clinic with a baseline. There is a relationship between the strength of the pelvic muscles assessed manually and that obtained by a perineometer in women with SUI. There was no relationship between these values of strength and quality of life perceived.Electronic supplementary materialThe online version of this article (doi:10.1186/s12905-014-0143-4) contains supplementary material, which is available to authorized users.

Isometric Shoulder Strength Reference Values for Physically Active Collegiate Males and Females

Background:It is common clinical practice to assess muscle strength during examination of patients following shoulder injury or surgery. Strength comparisons are often made between the patient’s injured and uninjured shoulders, with the uninjured side used as a reference without regard to upper extremity dominance. Despite the importance of strength measurements, little is known about expected normal baselines of the uninjured shoulder. The purpose of this study was to report normative values for isometric shoulder strength for physically active college-age men and women without history of shoulder injury.Methods:University students—546 males (18.8 ± 1.0 years, 75.3 ± 12.2 kg) and 73 females (18.7 ± 0.9 years, 62.6 ± 7.0 kg)—underwent thorough shoulder evaluations by an orthopaedic surgeon and completed bilateral isometric strength measurements with a handheld dynamometer. Variables measured included internal rotation, external rotation, abduction, supine internal rotation and external rotation at 45°, and lower trapezius in prone flexion.Results:Significant differences were found between the dominant and nondominant shoulder for internal rotation, internal rotation at 45°, abduction, and prone flexion in males and in internal rotation at 45° and prone flexion for females (P ≤ 0.01).

Determination of longitudinal compressive strength of long fiber composites by three-point bending of [0 m/90 n/0 p] cross-ply laminated strips

A new test method is proposed for measuring longitudinal compressive strength of composite laminates by three-point bending of cross-ply laminates. Optimal cross-ply configuration has been designed in order to get compressive stresses higher than tensile stresses. Thermal and mechanical stresses have been calculated based on the hypothesis of Classical Beam Theory. Cross-ply carbon/epoxy strips with different thicknesses and spans have been tested by three-point bending. Failures on the compressive side have been observed in all cases and no evidence of transverse cracking has been found. Experimental results agree well with compressive strength reference values. The possibility of determination of compressive and tensile strengths by three-point bending from a unique cross-ply lay-up has been also analyzed.

Lower Extremity Muscle Strength in 6- to 8-Year-Old Children Using Hand-Held Dynamometry

The purposes of the study were to establish isometric torque reference values for healthy 6- to 8-year-old children for 6 lower extremity muscles and determine the effects of gender, age, height, weight, and physical activity upon strength. A hand-held dynamometer was used to obtain force/torque values for 154 children. Age-referenced force/torque and cutoff values are provided for each muscle group. Torque increased with age and height for all muscles and with weight for all muscles except knee extensors. No gender differences were found. Children who participated in 3 or more hours per week in organized sports were stronger in 4 of 6 muscles; the number of hours spent in active play did not affect torque. This study provides hand-held dynamometer strength reference values to enable clinicians to determine if clients of the same age, height, and weight have muscle weakness.

Assessing grip strength in healthy individuals and patients with immune‐mediated polyneuropathies

Grip strength reference values for a portable dynamometer, the hand-held Vigorimeter, were calculated, and its validity, reliability, and responsiveness were examined in patients with immune-mediated polyneuropathies. We studied 530 healthy controls (age 5–93 years), 113 patients with stable polyneuropathy (83 with Guillain-Barré syndrome [GBS], 22 with chronic inflammatory demyelinating polyneuropathy [CIDP], and 8 with a gammopathy-associated polyneuropathy), and 20 patients with GBS or CIDP and changing clinical conditions (longitudinal group). An arm-disability scale was also assessed. Grip-strength reference values were calculated depending primarily on age and gender. Significant association was obtained between the Vigorimeter and the arm scale (in stable group, Spearman rank: r = −0.52 to −0.62; P ≤ 0.0005; in longitudinal group, linear regressions: r = 0.62–0.64, P < 0.0001). Good interobserver and intra-observer agreements (analysis of variance, r = 0.95–0.97) and high responsiveness (standardized response mean scores ≥ 0.8) were demonstrated for the Vigorimeter. These results emphasize the clinical usefulness of the Vigorimeter, particularly in patients with immune-mediated polyneuropathies. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 1393–1401, 2000.

Assessing grip strength in healthy individuals and patients with immune-mediated polyneuropathies.

Grip strength reference values for a portable dynamometer, the hand-held Vigorimeter, were calculated, and its validity, reliability, and responsiveness were examined in patients with immune-mediated polyneuropathies. We studied 530 healthy controls (age 5-93 years), 113 patients with stable polyneuropathy (83 with Guillain-Barré syndrome [GBS], 22 with chronic inflammatory demyelinating polyneuropathy [CIDP], and 8 with a gammopathy-associated polyneuropathy), and 20 patients with GBS or CIDP and changing clinical conditions (longitudinal group). An arm-disability scale was also assessed. Grip-strength reference values were calculated depending primarily on age and gender. Significant association was obtained between the Vigorimeter and the arm scale (in stable group, Spearman rank: r = -0.52 to -0.62; P </= 0.0005; in longitudinal group, linear regressions: r = 0.62-0.64, P < 0.0001). Good interobserver and intra-observer agreements (analysis of variance, r = 0.95-0.97) and high responsiveness (standardized response mean scores > or = 0.8) were demonstrated for the Vigorimeter. These results emphasize the clinical usefulness of the Vigorimeter, particularly in patients with immune-mediated polyneuropathies.