Prediction of back strength using anthropometric and strength measurements in healthy females

The Impact of Hand Strength on HbA1c, Body Mass Index and Body Composition by Group According to Sedentary Behaviour: Cross-Sectional Study in Japanese Patients with Type 2 Diabetes Mellitus

Background

The impact of hand strength in consideration of sedentary behaviour on diabetes management in patients with type 2 diabetes mellitus (T2DM) is unclear. The purpose of this study was to examine the impact of hand strength on HbA1c, body mass index (BMI) and body composition by group according to the duration of sedentary behaviour in Japanese patients with T2DM.

Methods

In this retrospective, cross-sectional, single-centre study, hand strength standardised by bodyweight (GS) and sedentary time (ST), were obtained and analysed in a total of 270 Japanese T2DM outpatients in 2021. After dividing the patients into four categories of median values (high and low GS, and long and short ST), odds ratios (ORs) for good control of HbA1c, BMI, waist circumference (WC) and intra-abdominal fat (IAF) were investigated using logistic regression models.

Results

The high GS/short ST group was found to have a significantly higher (OR = 2.01; 95% CI: 1.00, 4.03; P = 0.049) for controlled HbA1c compared with that of the low GS/long ST group. The high GS/short ST and the high GS/long ST groups had significantly higher ORs for controlled BMI, WC and IAF compared with the OR of the low GS/long ST group. In addition, the ORs were significantly increased with a positive trend in order from low GS/long ST, low GS/short ST, high GS/long ST, to high GS/short ST in all models (P < 0.001 for trend).

Conclusion

Hand strength, with modest effects from sedentary behaviour, could be helpful for diabetes management in T2DM patients.

The impact of grip strength, waist circumference, and body mass index on Hemoglobin A1c value: Cross-sectional study using outpatient clinical data in Japanese elderly patients with type 2 diabetes mellitus

AIM

Grip strength (GS) as a surrogate for muscular strength, waist circumference (WC) as a surrogate marker of visceral fat, and body mass index (BMI) as a surrogate marker of obesity should also be considered markers for the management of risks associated with type 2 diabetes mellitus (T2DM). However, in terms of the management of T2DM in elderly patients, the accentuated heterogeneity of sarcopenic change might modify the associations between those factors and glycemic control. In this cross-sectional study, we aimed to clarify the impact of GS, WC, and BMI on hemoglobin A1c (HbA1c) in elderly Japanese patients with T2DM.

METHODS

GS, WC, and BMI were measured in 327 patients. Odds ratios (ORs) and 95% confidence intervals (CIs) for good glycemic control (HbA1c < 7.0%) were investigated to analyze the three variables as numerical values by dividing them into tertiles. All results were expressed after adjustment was made for the confounders of age, sex, and number of diabetes medications being used by the study participants.

RESULTS

The ORs of GS, WC, and BMI for well-controlled HbA1c were 1.056 (95% CI, 1.016-1.098), 0.986 (95% CI, 0.960-1.013), and 1.032 (95% CI, 0.959-1.111), respectively. The OR of 3.726 (95% CI, 1.831-7.581) in the high tertile for GS was significantly higher than the OR in the low tertile, and no differences were observed among the tertiles for WC and BMI.

CONCLUSIONS

Based on that result, GS was found to have more potential as an effective marker of glycemic control than WC or BMI among elderly Japanese patients with T2DM. Geriatr Gerontol Int 2024; 24: 410-414.

Associations between grip strength, cardiorespiratory fitness, cardiovascular risk and mental health in forcibly displaced people from a Greek refugee camp

Muscular strength represents a specific component of health-related fitness. Hand grip strength is used as a simple and dynamic marker of maximum voluntary force of the hand and to estimate overall strength. Today, little is known about the relationship between grip strength and health in forcibly displaced populations. In the present study, we examined whether grip strength is associated with various health outcomes in a sample of forcibly displaced people living in a Greek refugee camp. The present analyses are part of a larger pragmatic randomized controlled trial. In this paper, cross-sectional baseline data of 143 participants (71 men, 72 women) will be presented. In addition to grip strength, the following physical and mental health outcomes were assessed: body weight and body composition, blood pressure, total cholesterol, low- and high-density lipoprotein cholesterol, triglycerides, blood glucose levels (HbA1c), post-traumatic stress disorder (PTSD) symptoms, depressive and anxiety symptoms, pain, and quality of life. Linear regression analyses were carried out to examine how grip strength is associated with the health outcomes, separately for absolute and normalized grip strength scores. Grip strength was positively and strongly associated with percentage muscle mass (normalized grip strength: Stand. B = 0.58, p < .001), whereas a negative association existed for percentage body fat (normalized grip strength: Stand. B = - 0.58, p < .001). No statistically significant associations occurred between grip strength and the other cardiovascular risk markers. In contrast, we found that participants with higher normalized grip strength reported higher levels of PTSD (normalized grip strength: Stand. B = 0.36, p < .05) and depressive symptoms (normalized grip strength: Stand. B = 0.29, p < .05). No significant association occurred between grip strength, anxiety, pain and quality of life. Measuring grip strength in forcibly displaced people can be a useful way to assess their overall muscle strength. Grip strength tests are easy to implement, and results can be used to assess the effects of specific intervention measures. Nevertheless, our results question the usefulness of grip strength as a marker of cardiovascular health and mental wellbeing in a refugee camp setting.

Handgrip strength assessment at baseline in addition to bone parameters could potentially predict the risk of curve progression in adolescent idiopathic scoliosis

Introduction

Adolescent idiopathic scoliosis (AIS) is characterized by deranged bone and muscle qualities, which are important prognostic factors for curve progression. This retrospective case-control study aims to investigate whether the baseline muscle parameters, in addition to the bone parameters, could predict curve progression in AIS.

Methods

The study included a cohort of 126 female patients diagnosed with AIS who were between the ages of 12 and 14 years old at their initial clinical visit. These patients were longitudinally followed up every 6 months (average 4.08 years) until they reached skeletal maturity. The records of these patients were thoroughly reviewed as part of the study. The participants were categorized into two sub-groups: the progressive AIS group (increase in Cobb angle of ≥6°) and the stable AIS group (increase in Cobb angle <6°). Clinical and radiological assessments were conducted on each group.

Results

Cobb angle increase of ≥6° was observed in 44 AIS patients (34.9%) prior to skeletal maturity. A progressive AIS was associated with decreased skeletal maturity and weight, lower trunk lean mass (5.7%, p = 0.027) and arm lean mass (8.9%, p < 0.050), weaker dominant handgrip strength (8.8%, p = 0.027), deranged cortical compartment [lower volumetric bone mineral density (vBMD) by 6.5%, p = 0.002], and lower bone mechanical properties [stiffness and estimated failure load lowered by 13.2% (p = 0.005) and 12.5% (p = 0.004)]. The best cut-off threshold of maximum dominant handgrip strength is 19.75 kg for distinguishing progressive AIS from stable AIS (75% sensitivity and 52.4% specificity, p = 0.011).

Discussion

Patients with progressive AIS had poorer muscle and bone parameters than patients with stable AIS. The implementation of a cut-off threshold in the baseline dominant handgrip strength could potentially be used as an additional predictor, in addition to bone parameters, for identifying individuals with AIS who are at higher risk of experiencing curve progression.

Is grip strength linked to body composition and cardiovascular risk markers in primary schoolchildren? Cross-sectional data from three African countries

OBJECTIVES

Muscular strength represents a specific component of health-related fitness. Hand grip strength (HGS) is used as an indicator for musculoskeletal fitness in children. HGS can also be used as a marker of cardiometabolic risk, but most available HGS data are derived from Western high-income countries. Therefore, this study examines whether HGS is associated with body composition and markers of cardiovascular risk in children from three sub-Saharan African countries.

DESIGN

Cross-sectional study.

SETTING

Public primary schools (grade 1-4) in Taabo (Côte d'Ivoire), Gqeberha (South Africa) and Ifakara (Tanzania).

PARTICIPANTS

Data from 467 children from Côte d'Ivoire (210 boys, 257 girls), 864 children from South Africa (429 boys, 435 girls) and 695 children from Tanzania (334 boys, 361 girls) were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Body composition (assessed via bioelectrical impedance analysis) was the primary outcome. Cardiovascular risk markers were considered as secondary outcome. Blood pressure was measured with an oscillometric monitor, and blood markers (cholesterol, triglycerides, glycated haemoglobin) via Afinion point-of-care testing. HGS (independent variable) was assessed with a hydraulic hand dynamometer. Inferential statistics are based on mixed linear regressions and analyses of covariance.

RESULTS

Across all study sites, higher HGS was associated with lower body fat, higher muscle mass and higher fat-free mass (p<0.001, 3.9%-10.0% explained variance), both in boys and girls. No consistent association was found between HGS and cardiovascular risk markers.

CONCLUSIONS

HGS assessment is popular due to its simplicity, feasibility, practical utility and high reliability of measurements. This is one of the first HGS studies with children from sub-Saharan Africa. There is a great need for further studies to examine whether our findings can be replicated, to develop reference values for African children, to establish links to other health outcomes, and to explore whether HGS is associated with later development of cardiovascular risk markers.

TRIAL REGISTRATION NUMBER

ISRCTN29534081.

The association between the kyphosis angle and physical performance in community-dwelling older adults

BACKGROUND

We investigated prospectively among community-dwelling older adults aged 65 years and over whether a larger kyphosis angle is associated with poorer physical performance (balance, muscle strength or both), and whether this association is unidirectional.

METHODS

ale and female participants performed a multicomponent physical performance test with subscores for gait, muscle strength and balance at baseline and after 2 years. Hand grip strength was also measured at baseline and at follow-up. The Cobb angle was measured on DXA-based Vertebral Fracture Assessments, made at the baseline and follow-up visit. Through linear and logistic regression analysis, we investigated the association between the kyphosis angle and physical performance and vice versa. We stratified for sex, and tested for effect modification by age and study center.

RESULTS

The mean kyphosis angle was 37° and 15% of the participants (n=1220, mean age 72.9±5.7 years) had hyperkyphosis (Cobb angle ≥50°). A larger kyphosis angle at baseline was independently associated with a poorer total physical performance score in women of the oldest quartile (≥77 years) in both the cross-sectional and longitudinal analyses (baseline B-0.32, 95%CI -0.56--0.08; follow-up B 0.32, 95%CI -0.55--0.10). There was no association between physical performance at baseline and kyphosis progression.

CONCLUSIONS

A larger kyphosis angle is independently associated with a poorer physical performance at baseline and over time, and the direction of this association is unidirectional. These results emphasize the importance of early detection and treatment of hyperkyphosis to prevent further worsening of the kyphosis angle, thereby potentially preserving physical performance.

Inductive Textile Sensor Design and Validation for a Wearable Monitoring Device

Textile sensors have gained attention for wearable devices, in which the most popular are the resistive textile sensor. However, these sensors present high hysteresis and a drift when stretched for long periods of time. Inductive textile sensors have been commonly used as antennas and plethysmographs, and their applications have been extended to measure heartbeat, wireless data transmission, and motion and gesture capturing systems. Inductive textile sensors have shown high reliability, stable readings, low production cost, and an easy manufacturing process. This paper presents the design and validation of an inductive strain textile sensor. The anthropometric dimensions of a healthy participant were used to define the maximum dimensions of the inductive textile sensor. The design of the inductive sensor was studied through theoretical calculations and simulations. Parameters such as height, width, area, perimeter, and number of complete loops were considered to calculate and evaluate the inductance value.

Kinematic and perceptual responses in heavy lifting and pulling: Are there differences between males and females?

This study investigated kinematic and perceptual differences between the sexes in a heavy lifting and pulling task. A 20 kg box was lifted from floor to chest height, and a 70 kg mannequin pulled across 20m. The effect of height, mass and average grip strength on kinematics and perceived workload was examined in 42 (19 females, 23 males) healthy individuals. A univariate linear regression analysis found females lifted with greater lumbar extension compared to males (p < 0.001), and adopted more hip (p = 0.006) and knee flexion (p = 0.036) in the pulling task. Females reported a greater perceived workload in both tasks (p < 0.001). After the multivariable analysis, only grip strength remained significant for perceived workload in the lift (p = 0.04), and height for knee flexion in the pull (p = 0.009). This highlights that height and strength are important factors driving kinematics and perceived workload. Clinicians may consider these factors in heavy manual tasks, more so than sex.

Trunk Muscle Activation Patterns Differ Between Those With Low and High Back Extensor Strength During a Controlled Dynamic Task

It is proposed that reduced function in one of the spinal systems (active, passive, and neural) outlined by Panjabi could increase the risk of experiencing a low back injury (LBI). Also proposed is that reduced function in any one system can be compensated for by adjusting the time-varying recruitment of trunk muscles. This study addressed whether those with reduced active system function (WEAK), measured as back extensor strength, would have different trunk muscle activation patterns than those with higher function (STRONG), and secondly whether this relationship would be modified following recovery from a LBI. Sixty men participated, 30 recently recovered from LBI (rLBI, 4–12 weeks post injury) and 30 who had not had a LBI in the last year (ASYM). ASYM and rLBI participants were separated into STRONG and WEAK sub-groups if their isometric back extensor strength was above or below their group median, respectively. Trunk electromyograms from 24 muscle sites were recorded during a highly controlled horizontal transfer task. Principal component analysis captured key muscle activation patterns (amplitude and temporal); then analysis of variance models tested for strength or group*strength effects on these patterns consistent with the two main objectives. Significant strength, or group by strength effects were found for 3/4 electromyographic comparisons. In general, the WEAK group required higher activation amplitudes of abdominal and back extensor muscles, and greater temporal responsiveness of back extensor muscles only to the changing external moments than those who were STRONG. Group by strength interactions found that participants in the rLBI group had greater differences between WEAK and STRONG participants for overall muscle activation amplitudes in both abdominal and back extensor muscles. This increase in muscle activation was interpreted as compensation for lower maximum force properties whereas the increased temporal responsiveness captured a greater need to modify the agonist back extensors muscle activation patterns only in response to changes in the dynamic moments. Interactions captured that the recent experience of pain (rLBI) modified the magnitude of adjustment in muscle activation patterns potentially adapting to an increased risk of instability (painful flare) events associated with a deficit (lower strength) of the active system.

Association between hand-grip strength and site-specific risks of major osteoporotic fracture: Results from the Japanese Population-based Osteoporosis Cohort Study

OBJECTIVES

To investigate the association between hand-grip strength and site-specific risks of major osteoporotic fracture.

STUDY DESIGN

Prospective cohort study.

MAIN OUTCOME

Associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip.

MEASURES

We enrolled 1342 postmenopausal women aged 50 years or more into baseline and follow-up surveys of the Japanese Population-based Osteoporosis Cohort Study in 1996, 1999, 2002, or 2006. Fracture events were ascertained by follow-up surveys until 2011 or 2012. The Cox proportional hazards model was used to estimate hazard ratios (HRs) of hand-grip strength on fracture event.

RESULTS

During a median follow-up of 15.2 years, 162 women sustained at least one osteoporotic fracture and 135 of these women sustained at least one major osteoporotic fracture, the larger group including 65, 38, 35, and 8 women with fractures of the distal forearm, vertebrae, hip, and proximal humerus, respectively. In the crude models, the associations between low hand-grip strength and increased risk of fracture at the distal forearm, vertebrae, and hip were significant; the HRs (95% confidence interval) of the lowest tertile of hand-grip strength were 2.02 (1.10-3.71), 11.35 (4.07-31.63), and 4.72 (1.79-12.47), respectively. Age adjustment attenuated the significance of hip fracture risk, and adjusting for bone mineral density attenuated the significance of distal forearm fracture risk. After additional adjustment for body mass index, history of diabetes mellitus, and calcium intake, the HR for vertebral fracture risk was 4.55 (1.56-13.27). When limiting the follow-up period to 5 and 10 years, low hand-grip strength was associated with an increased risk of distal forearm fracture independently of the aforementioned covariates; the HRs were 4.22 (1.12-15.95) and 2.52 (1.03-6.17), respectively.

CONCLUSIONS

Low hand-grip strength is specifically associated with the risk of distal forearm fractures within 10 years and clinical vertebral fractures within 15 years or more in Japanese postmenopausal women.

Handgrip strength measurement in patients with chronic obstructive pulmonary disease: Possible predictor of exercise capacity

BACKGROUND

Impaired exercise capacity is one of the most important prognostic factors for patients with chronic obstructive pulmonary disease (COPD). The 6-min walk test (6MWT) is a widely used method for assessing exercise capacity in patients with COPD. However, the 6MWT requires considerable effort from patients. Therefore, a less physically demanding, but also noninvasive, method is warranted. The objective of this study was to determine the predictors of the 6MWT distance (6MWD) in patients with COPD.

METHODS

This retrospective observational study enrolled 133 Japanese patients with COPD. All patients underwent the 6MWT, COPD assessment test (CAT), spirometry, respiratory muscle strength evaluation, body composition assessment, and handgrip strength (HGS) measurement. We examined the associations between the 6MWD and evaluated parameters.

RESULTS

From single regression analysis, the 6MWD was significantly correlated with age, CAT score, several spirometric measurements (e.g., percentages of forced vital capacity, forced expiratory volume in 1 s, and carbon monoxide diffusing capacity of the lungs [%DLCO]), respiratory muscle strength parameters (e.g., percentages of maximal expiratory and inspiratory pressures), skeletal muscle mass index, and HGS. In multiple regression analysis, age, CAT score, %DLCO, and HGS were independent predictors of the 6MWD. The %DLCO and HGS were strongly correlated as predictors of the 6MWD (p < 0.001).

CONCLUSIONS

We found that HGS was significantly correlated with the 6MWD compared with spirometric measurements or respiratory muscle strength parameters in Japanese patients with COPD, suggesting that HGS could be a simple and noninvasive predictor of the 6MWD in patients with COPD.

Epigenome-wide exploratory study of monozygotic twins suggests differentially methylated regions to associate with hand grip strength

Hand grip strength is a measure of muscular strength and is used to study age-related loss of physical capacity. In order to explore the biological mechanisms that influence hand grip strength variation, an epigenome-wide association study (EWAS) of hand grip strength in 672 middle-aged and elderly monozygotic twins (age 55–90 years) was performed, using both individual and twin pair level analyses, the latter controlling the influence of genetic variation. Moreover, as measurements of hand grip strength performed over 8 years were available in the elderly twins (age 73–90 at intake), a longitudinal EWAS was conducted for this subsample. No genome-wide significant CpG sites or pathways were found, however two of the suggestive top CpG sites were mapped to the COL6A1 and CACNA1B genes, known to be related to muscular dysfunction. By investigating genomic regions using the comb-p algorithm, several differentially methylated regions in regulatory domains were identified as significantly associated to hand grip strength, and pathway analyses of these regions revealed significant pathways related to the immune system, autoimmune disorders, including diabetes type 1 and viral myocarditis, as well as negative regulation of cell differentiation. The genes contributing to the immunological pathways were HLA-B, HLA-C, HLA-DMA, HLA-DPB1, MYH10, ERAP1 and IRF8, while the genes implicated in the negative regulation of cell differentiation were IRF8, CEBPD, ID2 and BRCA1. In conclusion, this exploratory study suggests hand grip strength to associate with differentially methylated regions enriched in immunological and cell differentiation pathways, and hence merits further investigations.

Association between handgrip strength and back strength in adolescent and adult cricket players

Background Although a significant amount of research has been conducted on handgrip strength and its association with anthropometric variables, very few researchers have focused on assessment of back strength and its relationship with anthropometric variables in cricketers. Objective To investigate the degree of correlation between handgrip strength and back strength in cricket players of different maturity levels and to find the correlations of handgrip strength and back strength with anthropometric variables of age, height, body weight and body mass index (BMI). Methods Twenty-four adolescents; aged 16.6 ± 0.8 years and 32 adult cricketers aged 24 ± 4.6 years were tested for height, body weight, BMI, hand grip strength and back strength. t values, Cohen's d and Pearson's correlation coefficients were calculated. Results Hand grip strength and back strength were not found to correlate with each other at p ≤ 0.05 in adolescent players while a statistically significant large sized correlation was observed in adult cricketers at p = 0.001. Back strength and body weight were found to have a statistically significant moderate sized correlation with each other (r = 0.453 in the adolescent group and r = 0.355 in the adult group). Significant positive correlations were observed for left hand grip strength with height, body weight and BMI and also between back strength and age in the adult population of cricketers. Conclusion A significantly large correlation exists between handgrip strength and back strength in adult cricketers with no such correlation found for adolescent cricketers. Data of the present study justify its utility in the case of selection, assessment and rehabilitation of cricket players.

Does grip strength on the unaffected side of patients with hemiparetic stroke reflect the strength of other ipsilateral muscles?

[Purpose] Grip strength is used as an indicator of overall body muscular strength. However, most studies on grip strength have been performed in healthy people, and no study has evaluated it in the unaffected side of patients with hemiparetic stroke. The purpose of this study was to determine if grip strength on the unaffected side of patients with hemiparetic stroke correlates with the strength of other ipsilateral musculature. [Subjects and Methods] The maximal strengths of the muscles on the unaffected side of 31 patients with hemiparetic stroke were measured, and correlation coefficients were calculated. [Results] The results revealed significant positive correlations between grip strength on the unaffected side and the strength of the other ipsilateral muscle groups, with relatively high correlations being observed for the upper extremity muscle groups. [Conclusion] This suggests that grip strength on the unaffected side of patients with hemiparetic stroke can be used as a simple way to estimate overall strength on that side.

Age as a moderator of the secular trend for grip strength in Canada and the United States

PURPOSE

To determine whether grip strength changed on average over recent decades at each of two age levels (children and adolescents versus adults) in Canada and the US.

METHODS

For each sex, weighted least squares regression analyses were performed on mean grip strength values as reported in studies conducted from the 1960s onwards.

RESULTS

Grip strength did not change significantly as a function of year tested in children and adolescents, whereas it declined as a negatively accelerated function of year tested in adults.

CONCLUSION

The results are contrary to what might be expected given that body weight has increased in both countries in recent decades and given that grip strength has been found to be positively correlated with body weight. It is suggested that there was a concurrent change in a factor that operated to counteract the effect of increased body weight on grip strength, a prime candidate being a decrease in levels of serum vitamin D. It is also suggested that the secular decline in adult grip strength can be explained by a factor that affects muscular function but which has a long latency period, a prime candidate here being obesity history.

Muscle activity and head kinematics in unconstrained movements in subjects with chronic neck pain; cervical motor dysfunction or low exertion motor output?

Background

Chronic neck pain after whiplash associated disorders (WAD) may lead to reduced displacement and peak velocity of neck movements. Dynamic neck movements in people with chronic WAD are also reported to display altered movement patterns such as increased irregularity, which is suggested to signify impaired motor control. As movement irregularity is strongly related to the velocity and displacement of movement, we wanted to examine whether the increased irregularity in chronic WAD could be accounted for by these factors.

Methods

Head movements were completed in four directions in the sagittal plane at three speeds; slow (S), preferred (P) and maximum (M) in 15 men and women with chronic WAD and 15 healthy, sex and age-matched control participants. Head kinematics and measures of movement smoothness and symmetry were calculated from position data. Surface electromyography (EMG) was recorded bilaterally from the sternocleidomastoid and splenius muscles and the root mean square (rms) EMG amplitude for the accelerative and decelerative phases of movement were analyzed.

Results

The groups differed significantly with regard to movement velocity, acceleration, displacement, smoothness and rmsEMG amplitude in agonist and antagonist muscles for a series of comparisons across the test conditions (range 17 – 121%, all p-values < 0.05). The group differences in peak movement velocity and acceleration persisted after controlling for movement displacement. Controlling for differences between the groups in displacement and velocity abolished the difference in measures of movement smoothness and rmsEMG amplitude.

Conclusions

Simple, unconstrained head movements in participants with chronic WAD are accomplished with reduced velocity and displacement, but with normal muscle activation levels and movement patterns for a given velocity and displacement. We suggest that while reductions in movement velocity and displacement are robust changes and may be of clinical importance in chronic WAD, movement smoothness of unconstrained head movements is not.

Decline in lumbar extensor muscle strength the older adults: correlation with age, gender and spine morphology

BACKGROUND

Muscle morphology, age and gender may be determinants of muscle strength in older adults. However, very few research studies have directly examined such correlation in the ageing spine. The aim of the study was to examine the correlation between lumbar extensor muscle strength, its muscle fibre angles, thoracolumbar curvature, age and gender in the older and younger adults.

METHODS

Muscle fibre angles of lumbar extensor muscles, thoracolumbar curvature and lumbar extensor muscle strength were examined in 26 young (mean age 27.9, SD 5.2) and 26 older (mean age 72.1, SD 5.9) participants. Pearson's correlation was employed to determine the association among lumbar extensor muscle fibre angle, thoracolumbar curvature, age, gender and lumbar extensor muscle strength. Multiple stepwise linear regression analysis was used to identify significant determinants of lumbar extensor muscle strength.

RESULTS

The results demonstrated a significant correlation between lumbar extensor muscle strength, muscle fibre angle, age and gender. In the step wise regression analysis, both gender and age were identified as the most robust determinant for lumbar extensor muscle strength in older adults. However, gender was the only determinant of muscle strength in the young.

CONCLUSION

These results suggest that the decline in the lumbar extensor muscle strength in older adults was more dependent on age when compared to younger adults.

Concurrent measurement of isokinetic muscle strength of the trunk, knees, and ankles in patients with lumbar disc herniation with sciatica

STUDY DESIGN

A cross-sectional study comparing normal subjects and patients with lumbar disc herniation (LDH) with sciatica.

OBJECTIVE

To simultaneously measure the isokinetic muscle strength of the trunk, knees, and ankles in both groups.

SUMMARY OF BACKGROUND DATA

Coordination between the trunk and lower extremity muscles is important for normal physical activity. Reduced trunk and knee muscle strength have been reported in patients with lower level LDH; however, ankle performance in these patients is still unknown.

METHODS

We recruited 43 normal subjects as controls and 33 patients with lower level LDH with sciatica. The isokinetic strength of the trunk, knees, and ankles was measured at 2 velocities in random order: 60°/s and 120°/s, and 60°/s and 180°/s for trunk and ankle strength and for knee strength, respectively.

RESULTS

The isokinetic trunk strength was significantly lower in the LDH group irrespective of test modes or velocity. Despite unilateral sciatica or test modes and velocity, the unilateral knee strength was significantly lower in the LDH group than that in the control group. Knee extension torque was also found to be significantly lower in the limbs with sciatica than in those without sciatica at the testing velocity of 180°/s (80.25 ± 24.88 vs. 95.42 ± 26.29 Nm, P < 0.05). Irrespective of unilateral sciatica or test velocity, ankle plantar flexion torque revealed to be significantly lower in the LDH group than the control group; however, dorsiflexion torque was not different. Significant correlations were demonstrated among the total muscle strength of the trunk, knees, and ankles in both groups.

CONCLUSION

Besides the lower trunk strength, concurrent lower unilateral knee and ankle plantar flexion but not dorsiflexion strength was demonstrated in the LDH subjects with unilateral sciatica, regardless of its location. As compared to the limbs without sciatica, an additional 14% reduction of knee extension torque at 180°/s was found in the limbs with sciatica in the LDH patients.

Is grip strength a predictor for total muscle strength in healthy children, adolescents, and young adults?

The primary purpose of this study was to examine whether grip strength is related to total muscle strength in children, adolescents, and young adults. The second purpose was to provide reference charts for grip strength, which could be used in the clinical and research setting. This cross-sectional study was performed at primary and secondary schools and the University of Applied Sciences. Three hundred and eighty-four healthy Dutch children, adolescents, and young adults at the age of 8 to 20 years participated. Isometric muscle strength was measured with a handheld dynamometer of four muscle groups (shoulder abductors, grip strength, hip flexors, and ankle dorsiflexors). Total muscle strength was a summing up of shoulder abductors, hip flexors, and ankle dorsiflexors. All physical therapists participated in a reliability study. The study was started when intratester and intertester reliability was high (Pearson correlation coefficient >0.8). Grip strength was strongly correlated with total muscle strength, with correlation coefficients between 0.736 and 0.890 (p < 0.01). However, the correlation was weaker when controlled for weight (0.485-0.564, p < 0.01). Grip strength is related to total muscle strength. This indicates, in the clinical setting, that grip strength can be used as a tool to have a rapid indication of someone's general muscle strength. The developed reference charts are suitable for evaluating muscle strength in children, adolescents, and young adults in clinical and research settings.