Maximum handgrip strength as a function of type of work and hand-forearm dimensions

Comparison of wrist range of motion and muscle strength in assembly workers with and without lateral epicondylitis

BACKGROUND

Lateral epicondylitis (LE), also called tennis elbow, is a common musculoskeletal disorder that causes pain in the elbow area and is highly prevalent in assembly workers who repeatedly move their wrists.

OBJECTIVE

The purpose of this study was to compare the wrist ROM and muscle strength of assembly workers with and without LE.

METHODS

Forty-five male assembly line workers (23 with LE) participated in the study. Participants had their wrist range of motion (flexion, extension, ulnar deviation, and radial deviation) and strength (wrist flexors, extensors, and hand grip) measured using Smart KEMA sensors.

RESULTS

Workers with LE showed significantly reduced wrist extension and radial deviation ROM compared to workers without LE, with no significant differences in wrist flexion and ulnar deviation ROM between groups. Workers with LE had significantly lower wrist extensor strength compared to workers without LE, and there was no significant difference in wrist flexor and grip strength between the two groups.

CONCLUSIONS

For workers with LE, the difference in wrist ROM and muscle strength will be useful for planning intervention and evaluating treatment outcomes for assembly workers with LE.

Normative reference values and predicting factors of handgrip strength for dominant and non-dominant hands among healthy Malay adults in Malaysia

INTRODUCTION

Handgrip strength (HGS) measures the maximum voluntary force of the hand, which has been used to assess individual health status indirectly. Although several factors related to HGS have been identified, studies among adults in Malaysia are lacking. This study aimed to provide the normative reference HGS values and determine its predictor factors among healthy adults of Malay ethnic in Malaysia.

METHODOLOGY

This study was a part of the Prospective Urban Rural Epidemiology (PURE) study carried out among adults aged between 35 to 70 years old residing in urban and rural Malaysian communities. A standardised questionnaire was used to assess the socio-demographic information and physical activity level of respondents who provided written informed consent to participate in this study. HGS was measured using Jamar's dynamometer. A total of 3,446 healthy adults of Malay ethnic were included in this study. Descriptive data were used to derive the normative reference values for HGS using means and standard deviations stratified by age and gender. The predictors of HGS were determined using a general linear model (GLM).

RESULTS

Mean HGS ranged from 38.48 (± 9.40) kg for the dominant hand of men aged 35-40 years to 16.53 (± 5.69) kg for the non-dominant hand of women aged 61-70 years. The ANOVA indicated that there was a significant descending trend of HGS as age increased for both genders (p < 0.05). The ANOVA also revealed that participants working in blue- or white-collar jobs had higher HGS than their counterparts who are homemakers (p < 0.05). The GLM shows that, age, occupation type, socio-economic status (SES), physical activity level and BMI significantly predicted dominant HGS among male and meanwhile, only age, SES and BMI significantly predicted dominant HGS among female.

CONCLUSION

HGS normative values provided herein can serve as a guide for interpreting HGS measurements obtained from healthy Asian adults especially Malay ethnic. The clinicians and researcher can use the established HGS reference values as comparison in their patients or participants. Furthermore, during a rehabilitation process, the clinicians and researchers could use the normal score ranges to document the progress of HGS and provide feedback to the patients. Further study with prospective study design is needed to determine the causal effect association of the predictors and HGS.

Lifestyle and physical fitness in adolescents with type 1 diabetes and obesity

Background

The association between Type 1 Diabetes Mellitus (T1DM) and obesity (Ob) is no longer unexpected due to unhealthy lifestyle mostly in adolescents. We compared clinical-biochemical characteristics, adherence to the Mediterranean Diet (MD), lifestyle habits and physical fitness across different weight categories of T1DM adolescents from Campania Region. As second aim, we assessed the relationship among lifestyle and physical fitness in these patients.

Methods

74 adolescents (35M; 39F; 13-18 y), with T1DM diagnosed at least 6 mo before the study, were enrolled at the Regional Center for Pediatric Diabetology of Vanvitelli University of Naples. Height, weight, Body Mass Index (BMI), BMI z-score, and Clinical Biochemical health-related parameters were determined. MD adherence, physical activity (PA) amount and sedentary habits were assessed by questionnaires. Handgrip strength, 2-Min Step test (2-MST) cardiorespiratory endurance and Timed up and go test (TUG) for agility and balance were used for physical fitness evaluation.

Results

Our sample included 22 normal weight (NW), 37 overweight (OW) and 15 with Obese (Ob) adolescents. Across the three groups, adolescents showed similar Clinical-Biochemical parameters, MD adherence, PA amount, mostly walking (9.3 h/w), daily video exposure (8.5 h/d) and similar handgrip or 2-MST performance. Better performance was observed in NW compared to OW or Ob for TUG (7 vs 8 vs 9 s; p < 0.05). A positive correlation was found between TUG test and BMI, while no correlation was found between HbA1c (glycated haemoglobin) and BMI z score or 2-MST.

Conclusions

T1DM adolescents did not meet the recommendations for active lifestyle, despite a medium/good adherence to MD, in particular in NW and OW youths. Sedentary habits correlated with a poor HbA1c. Further, reduced agility and balance were observed in adolescents with obesity compared to NW participants.Future research should be aimed to examine wider samples and to design health promotion interventions for T1DM adolescents.

Examination of the correlation between hand grip strength and muscle mass, balance, mobility, and daily life activities in elderly individuals living in nursing homes

BACKGROUND: Aging is a process that includes progressive physiological changes. Grip strength is an important indicator of current health in the elderly. OBJECTIVE: The aim of the study was to examine the correlation between dominant-hand grip strength (HGS) and cognitive function, mid-upper arm circumference, muscle-bone mass, balance, mobility, and daily life activities in elderly individuals living in nursing homes and determine the effect rates of these factors on HGS. METHODS: Seventy-two elderly individuals aged over 65 who lived in a nursing home were included in the study. Dominant HGS and mid-upper forearm circumference were measured. Muscle and bone masses were measured with bioelectrical impedance analysis. Mid-upper arm circumference was measured using a non-elastic tape. HGS was measured using a hand dynamometer. Cognitive function was evaluated with the Standardized Mini-Mental Test (SMMT); mobility and balance were evaluated with the Timed Up and Go Test (TUGT) and Berg Balance Scale (BBS); the Katz Activities of Daily Living Scale (KATZ ADL) was used to evaluate daily life activities. RESULTS: There was a significant correlation between HGS and muscle and bone masses (p < 0.001). A significant correlation was found between HGS and TUGT, ADL (p = 0.001, p = 0.016). There was no significant correlation between HGS and BBS (p = 0.2). There was a correlation between HGS and SMMT at the statistical significance limit (p = 0.055). On HGS, the Body Mass Index had a 64.9% effect; the muscle mass had a 30.9% effect; the TUGT had a 27.7% effect. These parameters were found to explain 59.9% of the variance. CONCLUSION: As a global indicator of muscle strength, HGS can be used to predict age-related functional changes. Approaches to increase physical activity levels in elderly can be effective in reducing age-related negativities.

Experiences of occupational therapy clinicians on the assessment and evaluation of adult handgrip strength

Introduction:

Handgrip strength (HGS) is commonly measured to assess hand function, however, little is known about how and why occupational therapists assess and interpret HGS. This study aimed to explore the experiences of occupational therapists who work with HGS. Additionally, the study explored what biological and functional factors occupational therapists believe influence adult HGS.

Method:

A qualitative study design utilising purposive sampling identified occupational therapy clinicians within Queensland, Australia who assess HGS. Data were collected from 19 participants using a semi-structured interview process. The interviews were transcribed verbatim and analysed using thematic analysis.

Results:

Variations of the American Society of Hand Therapists HGS testing procedure were used by the participants based on experience. When evaluating HGS, comparison to normative data was not always completed or seen to be valuable. Biological and functional factors such as height, hand length, occupation and lifestyle factors were considered to influence HGS.

Conclusion:

The results of this study provide insight into the various ways occupational therapists assess and evaluate HGS according to experience and practice context. These variations in assessment and evaluation of HGS along with the influence of an individual’s biological and functional factors need to be considered when interpreting HGS results.

Applications of new measures of population ageing using quantity and quality of remaining life years to India and selected states

In the latter part of the third stage, India is in demographic transition with declining fertility and mortality. This marked decline in death rates is driven by improvements in health conditions due to medical progress and better living conditions. The conventional measures of ageing do not account for the significant improvements in health and life expectancy, thus leading to a tendency to overestimate the impact of population ageing when these indicators are used. The old-age threshold in the conventional measures of ageing depends on chronological age. The present study estimated the multi-dimensional old-age thresholds (MOAT) based on the remaining life expectancy (RLE), self-rated health, activities of daily living (ADL), handgrip strength, and cognition in India and selected states. The standard population was derived for each dimension for 50 and over in states using the WHO Study on Global AGEing and Adult Health data. Keeping the dimensional characteristics as of the standard population, the estimated MOAT for India was 67 years where Maharashtra stands at the top (68.6), followed by, West Bengal (66.5) and Karnataka (66). A 64 year old woman was similar to 68.8 year old man, and a 66 year old rural person was equivalent to 68 year old urban person. The study suggests implications of MOATs on reducing the burden of ageing and increment in retirement age.

Grip strength in healthy Israeli adults: Comparison to internationally reported normative data

BACKGROUND: Grip strength is frequently used in research and clinical work and is commonly compared to normative data in clinical settings. To enable accurate interpretation of grip strength values, normative reference values should be close to the demographic, occupational, cultural and geographic characteristics of the individual tested. OBJECTIVE: Investigate the effects of gender, age, work-group and hand dominance on grip strength for the Israeli population, and to compare the grip strength to two normative studies from the United States. METHODS: A cross sectional study. The grip strength of 637 healthy adults was measured using a Jamar dynamometer. The effects for age, gender, hand dominance, and work strain were investigated. Israeli sample results were compared to US norms. RESULTS: Within the Israeli sample, a significant age effect was found for both men and women. This effect was most apparent among the 70+ age groups, in which grip strength was weaker than all the other groups. Males were significantly stronger than females, in both hands, and the dominant hand was significantly stronger, regardless of gender. Results also demonstrated a medium to large effect for type of work on grip strength portraying high manual strain workers to have stronger grip strength. Overall, the grip strength in the Israeli sample was weaker than both US samples. CONCLUSION: Clinicians should be cautious when comparing grip strength to published norms from a different culture/geographical region. The amount of manual strain invested in various occupational roles should be considered in the assessment and intervention process.

Normative data for handgrip strength in Iranian healthy children and adolescents aged 7-18 years: comparison with international norms

BACKGROUND

Grip strength is an essential component of physical fitness. The objective of this study was to develop normative handgrip strength data for Iranian healthy boys and girls comparing their handgrip strength with international reference values.

METHODS

Handgrip strength was measured in 2637 healthy children/adolescents (1391 boys and 1246 girls), aged 7-18 years, using a standard adjustable Jamar hand dynamometer (Model 5030 J1, Sammons Preston Rolyan, Bolingbrook, IL, USA). Body mass (kg) and stature (cm) were measured and body mass index was computed in kg/m2. The sample was stratified by gender, age, and hand preference.

RESULTS

Handgrip strength increased with age and was considerably higher in boys than in girls for all age groups (p < 0.001). Grip strength had a parallel and linear growth for both genders until the age of about 11 years and showed a steeper upward slope in boys than in girls thereafter. The findings of the current investigation were significantly different from those of the previously published normative data, especially for boys over the age of 12 years and girls in the age range of 7-18 years (p < 0.001). This difference was mainly in such a way that the Iranians had lower handgrip strength.

CONCLUSIONS

The differences between present results and those of similar available in the literature in this field emphasize the significant role of using normative data specific to a particular population in research or clinical settings.

Are there sex differences in physiological parameters and reaction time responses to overload in firefighters?

Male and female firefighters work side-by-side in the same in strenuous and risky conditions. Anthropometrics, physiological, and reaction time (mean of reaction time -MRT-, and errors made -E) parameters of 12 Female and 13 Male firefighters were compared. Effect of overload (step test with and without equipment) on the MRT and E were analyzed on 3 trials (T1 = 1-1s, T2 = 0.5-1s, T3 = 0.5–0.5s), compared with a pre-test condition (basal). T-test between males and females was applied to assess differences (p<0.05) in all parameters. ANOVA with repeated measures and Bonferroni on 3 conditions of step test between males and females was applied in reaction time variables. Between MRT and E, in T1, T2 and T3 trials and the 3 test conditions, ANCOVA models with interactions were used. Differences (p<0.05) in anthropometric, physiological and reaction time data emerged across groups, and on the 3rd trials (T3 vs T1 and T2) in reaction time parameters of each group. ANCOVA showed differences (p<0.001) in E among trials. Post hoc showed significant differences in T1vsT3 and T1vsT2. MRT x trial interaction was extremely significant (P<0.001). Implementing fitness and reaction time exercise programs is important to decrease the injury risk and increase work capacity in firefighters with reference to female workers.

Hand functionality in dentists: the effect of anthropometric dimensions and specialty

Objectives. This study aimed to investigate the relationship between dentists' hand functionality (handgrip, tip-to-tip pinch, key pinch and palmar pinch strengths) and dental specialty (maxillofacial surgery, endodontics, pediatric dentistry), socio-demographic factors and hand-forearm anthropometric dimensions. Methods. A cross-sectional study was designed in which 720 certified dentists (330 males and 390 females) voluntarily participated in the study. A tape measure (±0.1 cm) and a digital caliper (±0.1 mm) were used to measure anthropometric dimensions. A Jamar dynamometer and pinch gauge were used to measure hand strength variables. Results. Hand strengths decreased with age and clinical experience, and were always greater in male than female dentists. Maxillofacial surgeons aged 35-39 years attained the highest values of handgrip and key pinch strengths, while endodontists aged 30-34 years attained the peak values of tip-to-tip pinch strength. Among the measured hand dimensions, forearm circumference was significantly greater in maxillofacial surgeons compared with endodontists and pediatric dentists. Conclusion. Hand functionality is specialty-related among dentists because distinct dental specialties expose practitioners to different task demands. Like any other manual workers, dentists need more ergonomic and usable hand tools tailored not only to the intended application but also to the anthropometry of users.

Investigation of hand muscle fatigue and its influential factors in manual tasks

Muscle fatigue (MF) can lead to musculoskeletal disorders (MSDs) in the long term; however, it can be managed if the causes are well known. This study aimed to examine the grip force (GF) and grip fatigue (GFa) of employees with light, moderate and heavy manual tasks using a dynamometer and find their possible relationship with other factors. The nature of heavy manual tasks led to more experience of GFa and GF of the right hand. Moreover, the equal need for both hands in occupations with light and moderate manual tasks is the reason for more GFa in the left hand. In this primary study, the height, weight and age of subjects and their exposure to vibration had a decisive effect on GF. In order to determine the accurate effects of the aforementioned risk factors on MF, it is recommended for future studies to be performed on larger populations.

Analysis of hand-forearm anthropometric components in assessing handgrip and pinch strengths of school-aged children and adolescents: a partial least squares (PLS) approach

Background

The purpose of this study was to examine the influence of hand-forearm anthropometric dimensions on handgrip and pinch strengths among 7–18 years children and adolescents and to investigate the extent to which these variables can be used to predict hand strength.

Methods

Four types of hand strengths including handgrip, tip to tip, key, and three-jaw chuck pinches were measured in 2637 healthy children and adolescents (1391 boys and 1246 girls) aged 7–18 years using standard adjustable Jamar hydraulic hand dynamometer and pinch gauge. A set of 17 hand-forearm anthropometric dimensions were also measured with an accurate digital caliper and tape measure.

Results

No significant differences were found between the hand strengths of boys and girls up to the age of 10 years. Gender related differences in handgrip and pinches were observed from the age of 11 years onwards, with boys always being stronger. The dominant hand was stronger than the non-dominant hand (8% for handgrip and by about 10% for all three types of pinches). The strongest correlations were found between the hand length and hand strengths (r > 0.83 for handgrip and three all pinches; p < 0.001, 2-tailed). Based on the partial least squares (PLS) analysis, 8 out of 17 anthropometric indices including hand length, hand circumference, thumb length, index finger length, middle finger length, and forearm length had considerable loadings in the PLS analysis, which together accounted for 46% of the total variance.

Conclusions

These results may be used by health professionals in clinical settings as well as by designers to create ergonomic hand tools.

The ratio standard is not adequate for scaling handgrip strength in judo athletes and nonathletes

This study aimed to analyze if the ratio standard or the allometry is the best scaling methods of handgrip strength (HGS) for body mass (BM) in judo athletes and nonathletes, and to verify if the HGS mean values are higher in judo athletes than nonathletes when the BM effect is removed. One hundred forty-two individuals, being 88 judo athletes and 54 non-athletes participated in this study. The maximal isometric HGS was measured in judo athletes and nonathletes in the preferred hand. Only the allometry method was able to remove the BM effect of HGS. The al-lometric exponents found for athletes was b=0.68 and b=0.563 for non-athletes. A common allometric exponent was identified as (b=0.64) for comparing judo athletes and nonathletes. However, neither was able to allow for the comparison between groups due to a distortion of (bias; P<0.01). Thus, an index (HGS_INDEX) was proposed to allow within-group (judo athletes and nonathletes) and between-group (judo athletes vs. nonathletes) comparison, removing the effect of BM. In summary, the allometric exponent based on the theory of geometric similarity (b=0.67) was able to remove the BM effect of HGS in judo athletes. An index (HGS_INDEX) is suggested for classification (or rank) of the judoka in relation to the expected average of HGS.