Total Grip Strength Research Articles

The effect of comorbidities on the clinical profile and outcomes of surgery for carpal tunnel syndrome.

<b><br>Introduction:</b> The results of some studies show that predictors of less favourable outcomes of surgery for carpal tunnel syndrome might include the presence of comorbidities, such as diabetes and thyroid gland diseases. The role of these factors has not been clearly determined, but in most trials the patients burdened with comorbidities conducive to CTS are excluded from the analysis.</br> <b><br>Aim:</b> The aim of this study was to investigate the effect of concomitant diseases on the clinical profile and outcomes of surgery for carpal tunnel syndrome.</br> <b><br>Material and methods:</b> The study group consisted of 1117 patients - 909 women (81%) and 208 men (19%) - at a mean age of 63 years. A total of 972 patients (87%) declared having at least one comorbidity, whereas 145 patients (13%) declared no comorbidities. The measurements were performed preoperatively and at 6 months postoperatively; they included pain intensity, total grip and key-pinch strength, digital sensibility and hand function with Levine's questionnaire.</br> <b><br>Results:</b> At baseline, the patients with comorbidities had significantly worse digital sensiblility, weaker total grip strength and greater functional impairment of the hand, but only grip strength reached the minimal important difference (3.5 kg). Carpal tunnel release resulted in significant improvement in the tested variables for all patients, although the outcomes at 6 months were less favourable for those with comorbidities with regard to digital sensiblility, total grip and pinch strength and function of the hand. All these differences were statistically significant, but only grip strength reached the minimal important difference (2.9 kg).</br> <b><br>Conclusion:</b> The results of this study show that comorbidities in patients suffering from CTS had a statistically and clinically significant negative effect only on the total grip strength pre- and postoperatively, and no significant effect on the outcome of surgery, which was satisfactory in all patients.</br&gt.

Muscle Strength, Physical Fitness, Balance, and Walking Ability at Risk of Fall for Prefrail Older People.

This study was to explore the relationship of older adults' demographic information, physiological indices, and stages of frailty with their risk of falling. In the cross-sectional study, a total of 221 older adults with the mean age 74.9 (SD = 6.8) years old were surveyed by senior fitness test. Results were observed in terms of participants' physical fitness, with significant differences being observed in the correlations of left-hand grip strength (t = 5.05, p < .000), right-hand grip strength (t = 6.03, p < .000), and total grip strength (t = 5.70, p < .000), time up and go test (t = -6.25, p < .000), and 30-sec chair stand test (t = 7.19, p < .000) with the risk of falling. According to the logistic regression analysis results, long-term medication (OR = 0.12, 95% CI =0.02-0.62, p < .01) and right-hand grip strength (OR = 0.86, 95% CI =0.76-0.97, p < .01) are the main predictors of older adults' risk of falling. Older females with low education, history of falls, weaker grip strengths; taking longer to finish the TUG test; and standing fewer times during the 30-second chair stand test were at risk of fall. In prediction, older people using long-term medication were at lower risk of falling, and the greater the hand grip strength was, the lower the fall risk was. According to the research results, nursing personnel must develop care programs and improve older adults' risk of falls.

Lean Mass, Muscle Strength, and Muscle Quality in Retired Rugby Players: The UK Rugby Health Project.

Although athletes from sports such as rugby have greater lean mass and strength during their playing careers, little is known about these characteristics post-retirement. Therefore, this study investigated lean mass, strength, and muscle quality in retired elite and amateur rugby players and non-contact athletes. Retired elite male rugby players (n=42, 43.9±10.3 y; 101.1±13.4 kg; 1.82±0.09 m), amateur rugby players (n=46, 48.0±10.5 y; 98.9±16.6 kg; 1.79±0.07 m) and non-contact athletes (n=30, 51.3±12.5 y; 91.3±13.4 kg; 1.79±0.07 m) received one total body dual-energy X-ray absorptiometry assessment of appendicular lean mass (ALM) and ALM index (ALMI). Grip strength was measured, and muscle quality (grip strength/unit of arm lean mass) was calculated. Sarcopenia was identified as ALMI<7.23 kg/m2 and handgrip strength<37.2 kg. Total lean mass, ALM and grip strength were greater in the elite rugby compared to amateur rugby and non-contact groups (p<0.01). There were no significant differences in muscle quality or sarcopenia prevalence. Retired elite rugby players had greater lean mass and grip strength than amateur rugby and non-contact athletes, although muscle quality was similar. The greater lean mass and strength might reflect genetic influences or previous participation in a highly physical sport.

Prevalence and determinants of physical frailty among people living in residential aged care facilities: a large-scale retrospective audit

BackgroundPhysical frailty is associated with increased risk of falls, hospitalisation and mortality. There is a dearth of information on physical frailty of older adults living in residential aged care. This study aimed to describe physical frailty in aged care residents and investigate possible determinants of frailty.MethodA retrospective audit of resident records was undertaken across 14 residential aged care facilities. Data were extracted on all consenting residents who had completed measures relating to frailty (Short Physical Performance Battery SPPB; grip strength). All data of the first record of measures were extracted, resident characteristics, and the time from admission to assessment. Summary statistics were completed. Differences between sub-groups were explored (Mann-Whitney U, Kruskall-Wallis Ranked tests). Associations between variables were explored with Chi-squared and Pearson correlations. Determinants of physical frailty were determined with linear regression analyses. Alpha (2-sided) was 0.05.ResultsData were extracted for 1241 residents (67% female), with a mean age of 86.0 (7.6) years. Males had a significantly lower time from admission to assessment of frailty (p ≤ 0.001). The average SPPB score was 4.1 (3.3), 75% of residents were frail and 19% pre-frail. Bivariate analyses indicated no significant relationships between grip strength and SPPB score, but significant differences for grip strength, where males were significantly stronger (males 20.2 ± 8.3 kg; females 12.4 ± 5.4 kg; p ≤ 0.001). There was a significant positive relationship between SPPB total score and grip strength, gender (p ≤ 0.001), and marital status (p = 0.049) and a negative relationship between time from admission to assessment and SPPB total score (p ≤ 0.001). There were significant negative relationships between gender (p ≤ 0.001) and age (p ≤ 0.001), and time from admission to assessment (p ≤ 0.001) with grip strength.ConclusionOlder adults living in residential aged care have a high level of physical frailty which may lead to increased risk of adverse outcomes. Time in the residential aged care setting and age appear to predict physical frailty. There is a need for a consistent battery of measures to continually monitor frailty and programs to address the high levels of frailty in residential aged care.

Evaluation of the Quantitative Myasthenia Gravis Score and Grip Strength in Chinese Patients With Myasthenia Gravis: An Observational Study.

Introduction: The quantitative myasthenia gravis score is a commonly used scale for evaluating muscle weakness associated with myasthenia gravis (MG). It has been reported that some items used in the scale have low discriminative properties. However, there has been no research investigating the applicability of the quantitative MG score (QMGS) in Chinese patients with MG. In addition, the scoring method and ranges of grip strength items in QMGS need to be further evaluated.Methods: This study included 106 Chinese patients with MG, enrolled between September 2020 and February 2021, who were evaluated using the QMGS. Each item in the QMGS was analyzed for distribution. Three methods of evaluating grip strength, grip strength decrement, maximum grip strength, and relative grip strength, were compared. The correlation between the QMG total score minus grip strength score, and three evaluating methods, was analyzed.Results: The grip strength, swallowing, speech, diplopia, ptosis, and facial muscles items showed a clustered distribution. Most patients (94%) presented their maximum grip strength in the first four grip strength measurements. The QMG total score minus the grip strength score had a weak correlation with grip strength decrement (R grip r = 0.276; L grip r = 0.353, both p < 0.05) and moderate correlations with maximum grip strength (R grip r = −0.508; L grip r = −0.507; both p < 0.001) and relative grip strength (R grip r = −0.494; L grip r = −0.497, both p < 0.001).Conclusions: This study suggested that partial items in the QMGS have low discriminative properties for Chinese populations and the maximum grip strength value is the better method to evaluate grip strength compared to the other two scoring methods. Based on the quartiles of maximum grip strength, we propose new scoring ranges for the grip strength items.

Digital Replantations: Comparison Veins Anastomoses first versus Arteries Anastomoses first.

This retrospective study analyses the effect performing veins anastomoses before arteries anastomoses in digital replantation. 38 adult patients with replantation of 12 thumbs and 39 fingers, in whom the veins anastomoses were performed prior to the arteries anastomoses, were compared with 29 patients with replantation of 9 thumbs and 30 fingers, in whom the arteries anastomoses were done first, with respect to the survival rate, total active motion, grip strength, and duration of the replantation. There was no significant difference between the two groups with respect to the survival rates, total active motion, and grip strength, while the duration of the replantation was significantly shorter in patients, in whom the veins anastomoses were performed prior to the arteries anastomoses (2 hours and 50 minutes versus 3 hours and 42 minutes; p < 0.001). Performing veins anastomoses before arteries anastomoses in digital replantations reduces the replantation time significantly without influencing the survival rate and the clinical outcome.

Estimation Of 5 th (small) Digit’s Contribution To Grip Strength, Bicep Curls And Dead Hangs

There are many conditions that can affect the 5th (small) digit. However, there is limited data comparing dominant hand grip strength, pre and post injury. It has been shown that the 5th digit contributes 14% of total grip strength in handheld dynamometer (HHD) tests. However, the contribution of the 5th digit in activities like bicep curls and dead hangs is currently unknown. PURPOSE: To examine the 5th digit’s contribution to grip strength, bicep curls and dead hangs performance in healthy young adults. METHODS: 15 individuals (24.8 ± 2.8 years) participated in 1 session under 2 conditions: using 4 digits with digit-5 being taped into extension with 2 tongue depressors and athletic tape bilaterally and using all 5 digits. For each condition participants performed 3 tasks: grip strength using an HHD with their dominant hand, bicep curls to failure with their dominant hand using a dumbbell of 10% of their body weight, and dead hang to failure. They performed all 3 tasks for a condition, before moving to the next condition. Two-minute rest intervals were taken between tasks. One-tailed paired samples t-tests were used for grip strength and dead hang times, and a chi squared test was used for bicep curls reps. RESULTS: The grip strength, normalized by height, was significantly higher when using 5 digits (by 36.4%, p < 0.001). For bicep curls, 5-digit reps were significantly higher (by 14.1%; p < 0.05). For dead hang time, normalized by weight, 5-digit hang times were significantly longer (by 21.4%, p = 0.02). CONCLUSION: This study demonstrated an increase in performance of grip strength, bicep curls and dead hangs with the inclusion of the 5th digit; which is greater than its contribution of 14%. Additional studies need to be performed to see if bicep curls and dead hang time can be used to accurately predict grip strength.Table 1: Mean (SD) of Grip strength, bicep curls repetitions and dead hang times

Assessment of grip-motion characteristics in carpal tunnel syndrome patients using a novel finger grip dynamometer system

BackgroundGrip strength measurement is widely used in daily medical practice, and it has been reported that the grip strength decreases in patients with carpal tunnel syndrome (CTS). However, conventional grip dynamometers evaluate only the maximum power of total grip strength and cannot measure the time course of grip motion. In this report, we aimed to determine the grip characteristics of CTS patients by measuring the time course of each finger’s grip motion and to analyze the relationship between finger grip strength and subjective symptoms using this new grip system.MethodsThe grip strength of each finger was measured using the new grip system that has four pressure sensors on the grip parts of each finger of the Smedley grip dynamometer. We analyzed the time course of grip motion and relationship between finger grip strength and subjective symptoms in 104 volunteer and 51 CTS hands. The Japanese Society for Surgery of the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH) and the Disability of Arm, Shoulder, and Hand questionnaire (DASH) were used as subjective evaluation scores.ResultsIn the CTS group, the grip time with the index, middle, and ring fingers was longer, and the time at which strength was lost after reaching the maximum was earlier. Patients with severe subjective symptoms tended to not use the index and middle fingers during grip motion.ConclusionsThis new system that measures each finger’s grip strength at one time and record the time course of grip motion could quantify a patient’s symptoms easily and objectively, which may contribute to the evaluation of hand function.

Abstract A25: Withaferin A ameliorates ovarian cancer-induced cachexia through regulation of NF-kB/NLRP3 signaling

Abstract A majority of ovarian cancer patients exhibit clinical symptoms of cachexia, which accounts for up to 30% of cancer deaths depending on the oncologic setting. Withaferin A is a steroidal lactone with anti-inflammatory properties and is known to inhibit the growth of ovarian cancer and reduce metastasis through targeting cancer cells and cancer stem cells. The purpose of this study was to investigate whether Withaferin A could ameliorate the cachectic phenotype induced by ovarian cancer. We believe that treatment with Withaferin A could rescue body composition and muscle strength changes. The ovarian cancer cell line A2780 was xenografted into severely immunodeficient NSG mice via an intraperitoneal (i.p.) injection. Control mice received an i.p. injection of sterile saline. Following an engraftment period, mice were treated with vehicle or Withaferin A via i.p. injection every 3 days until the end of the study. Body weight and grip strength were assessed on a weekly basis. DEXA scan was performed post mortem, followed by collection/sectioning/staining of tumor samples and various skeletal muscle tissue. Withaferin A treatment significantly reduced the mortality rate associated with ovarian cancer. Treatment with Withaferin A inhibited an accumulation of adipose tissue within the thoracoabdominal region, associated with ovarian cancer progression. Low doses of Withaferin A were protective for forelimb and total limb grip strength, whereas higher doses were initially protective but resulted in a significant reduction. Further, Withaferin A ameliorated the reduction in myofibrillar cross-sectional area induced by ovarian cancer. Additionally, treatment with Withaferin A completely inhibited the slow-to-fast myofiber-type conversion seen in the settings of cancer cachexia. Lastly, using immunohistochemical staining and qPCR, we demonstrate that Withaferin A causes a downregulation of NF-kB-dependent proinflammatory cytokines and inhibits activation of the NLRP3 inflammasome, which are known to mediate cachectic signaling. Collectively, we provide preliminary data indicating that in ovarian cancer-induced cachexia, body composition changes and weakening of the skeletal muscle can be ameliorated through a downregulation of NF-kB-NLRP3 signaling. Citation Format: Alex R. Straughn, Mariusz Z. Ratajczak, Sham S. Kakar. Withaferin A ameliorates ovarian cancer-induced cachexia through regulation of NF-kB/NLRP3 signaling [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A25.

An analysis of patient's and disease related factors predictive of the outcomes of surgery for carpal tunnel syndrome.

Outcomes of surgery for carpal tunnel syndrome may differ in relation to certain factors like age, duration of symptoms, clinical and electrophysiological severity. The objective of this study was an investigation into the hypothesis that several factors are predictive of results of surgical treatment of the condition. The pre- and postoperative records of 1,117 patients: 909 women (81 %) and 208 men (19 %) with a mean age of 63 years were analysed. Outcomes recorded in the sensory and functional severity scores of the Levine questionnaire were dichotomized into achieving or not-achieving a minimally clinically important difference. The effect of selected variables: sex, age, duration of symptoms, clinical and electrophysiological severity of and presence of comorbidities on outcomes of surgery at 6 months was investigated. Univariate and multivariate analysis of covariates based on sex, age, duration of the disease and its clinical severity showed female gender and worse baseline symptom severity scores to be significant predictors for an improvement following carpal tunnel syndrome surgery. It showed also younger age, shorter duration of symptoms and higher baseline symptom severity scores to be predictive of a greater improvement of total grip strength, and younger age to be predictive of a greater pain cessation following surgery. Of all considered patient's and disease related factors, the baseline clinical severity expressed in the Levine symptom severity scores had appeared to be the strongest predictor of better outcomes of surgery for carpal tunnel syndrome.

Force distribution of a cylindrical grip differs between dominant and nondominant hand in healthy subjects.

Grip strength and load distribution of the hand are important parameters for evaluating hand function. The purpose of this study was to analyze and compare grip force and load distribution of dominant and nondominant hands in right-handed healthy subjects. Gripping measurements were performed on 40 healthy right-handed subjects using a cylindrical gripping device. Two different cylinders with circumferences of 150mm (small cylinder)and 200mm (large cylinder), respectively, were used for the measurements. Subjects were assigned to either the small or the large cylinder with respectto their hand size.Maximum and mean force applied during three intervals of gripping as well as the percent contribution of each digit, thenar, and hypothenar in relation to the total load applied were acquired. Values of dominant and nondominant hands were compared. Percent contribution of mean grip strength differed for the thumb (p = 0.007), ring finger (p < 0.001), little finger (p = 0.047), and palm (p < 0.001). Comparing the dominant and nondominant side, the dominant hand showed a lower contribution of the thumb, ring finger, and little finger, but a higher contribution of the palm. When analyzing maximum grip, percent contribution of the small fingers was equal between dominant and nondominant side (p = 0.1). Differences between dominant and nondominant thumb, ring finger, and palm persisted (p = 0.007, p = 0.001, p = 0.005, respectively). No differences could be shown for the index finger, middle finger, thenar, and hypothenar when analyzing both mean and maximum force. Percent contribution of the thumb and the fingers to total grip strength differed between dominant and nondominant hands with a change in distribution when assessing maximum grip force. In right-handed subjects, thumb and ring finger have important roles during gripping.

Long-term functional, subjective and psychological results after single digit replantation

ObjectiveThe aim of this study was to analyse the long-term functional, subjective, and psychological results after single-digit replantation. MethodsThirty cases of digital replantation (14 thumbs, 12 index fingers, 2 middle fingers, 1 ring finger, and 1 little finger) in 30 patients (7 females and 23 males) with a mean age of 44.2 years (20–65 years) were evaluated at the end of a mean follow-up time of 36 months (19–50 months). The active range of motion of joints, grip and pinch strength, cutaneous sensibility, upper-extremity functioning, and subjective satisfaction were determined using the Disability of Arm, Shoulder, and Hand (DASH) questionnaire and the Michigan Hand Outcomes questionnaire (MHQ). Psychological sequelae, including depression, anxiety, and posttraumatic stress disorder (PTSD), were assessed. A correlation analysis among variables was also performed. ResultsThe mean score for the DASH questionnaire was 6.6 (range: 0–39.2). The symptom of cold intolerance occurred in 53% of the patients. Two patients were diagnosed with depression, and only one patient exhibited PTSD. The DASH score had a good statistical correlation with total grip strength, pinch grip strength, and static two-point discrimination (S-2PD) (P < 0.05). Several aspects of the MHQ were also statistically relevant to some or all of the three objective results. Furthermore, the grip strength showed significant correlation with DASH and most aspects of the MHQ in multivariate logistic regression analysis (P < 0.05). ConclusionTotal grip strength is the most important factor positively related to subjective outcomes. The incidence rates of psychological symptoms after digit replantation are very low at long-term follow-up. Level of evidenceLevel IV, therapeutic study.

Effects of resistance training on body composition and functional capacity among sarcopenic obese residents in long-term care facilities: a preliminary study

BackgroundAging-related loss of muscle and strength with increased adiposity is prevalent among older people in long-term care (LTC) facilities. Studies have shown that people with sarcopenic obesity (SO) are at high risk of declining physical performance. At present, no interventional studies on residents with SO in nursing homes have been conducted in the literature. The objectives of this study include appraising the changes in body composition and physical performance following resistance training among residents with SO in LTC facilities.MethodsThis study used a quasiexperimental research design. Residents who are 60 years of age or above and have been living a sedentary lifestyle in LTC facilities for the past 3 months will be eligible for inclusion. The intervention group engaged in chair muscle strength training twice a week for 12 weeks, whereas the control group underwent the usual care. The main variables were physical parameters of being lean and fat, the strength of grip and pinch, and a functional independence measure using descriptive analysis, chi-squared test, t-test, and generalized estimating equation for statistical analysis through SPSS.ResultsA total of 64 respondents with SO completed the study. After training, total grip strength (p = 0.001) and total pinch strength (p = 0.014) of the intervention group differed significantly from those of the control group. The right grip strength of the intervention group increased by 1.71 kg (p = 0.003) and the left grip strength improved by 1.35 kg (p = 0.028) compared with baseline values. The self-care scores of the intervention group increased by 2.76 points over baseline scores, particularly for the action of dressing oneself. Although grip strength and self-care scores improved more among those in the intervention group, body fat and skeletal muscle percentages did not differ significantly between the groups after training (p > 0.05).ConclusionsResistance exercises for elderly residents in LTC facilities may play an important role in helping them maintain physical well-being and improve muscle strength.Trial registrationClinicaltrials.gov, number NCT02912338. Retrospectively registered on 09/21/2016.

Evaluation of the Contributions of Individual Finger Forces in Various Submaximal Grip Force Exertion Levels

Objective:The aim of this study is to evaluate contributions of individual finger forces associated with various levels of submaximal voluntary contraction tasks.BR Background: Although many researches for individual finger force have been conducted, most of the studies mainly focus on the maximal voluntary contraction. However, Information concerning individual finger forces during submaximal voluntary contraction is also very important for developing biomechanical models and for designing hand tools, work equipment, hand prostheses and robotic hands. Due to these reasons, studies on the contribution of individual finger force in submaximal grip force exertions should be fully considered.BR Method: A total of 60 healthy adults without any musculoskeletal disorders in the upper arms participated in this study. The young group (mean: 23.7 yrs) consisted of 30 healthy adults (15 males and 15 females), and the elderly group (mean: 75.2 yrs) was also composed of 30 participants (15 males and 15 females). A multi-Finger Force Measurement (MFFM) System developed by Kim and Kong (2008) was applied in order to measure total grip strength and individual finger forces. The participants were asked to exert a grip force attempting to minimize the difference between the target force and their exerted force for eight different target forces (5, 15, 25, 35, 45, 55, 65, and 75% MVCs). These target forces based on the maximum voluntary contraction, which were obtained from each participant, were randomly assigned in this study.BR Results: The contributions of middle and ring fingers to the total grip force represented an increasing trend as the target force level increased. On the other hand, the contributions of index and little fingers showed a decreasing trend as the target force level increased. In particular, Index finger exerted the largest contribution to the total grip force, followed by middle, ring and little fingers in the case of the smallest target force level (5% MVC), whereas middle finger showed the largest contribution, followed by ring, index and little fingers at the largest target force levels (65 and 75% MVCs).BR Conclusion: Each individual finger showed a different contribution pattern to the grip force exertion. As the target force level increase from 5 to 75% MVC, the contributions of middle and ring fingers showed an increasing trend, whereas the contributions of index and little fingers represented a decreasing trend in this study.BR Application: The results of this study can be useful information when designing robotic hands, hand tools and work equipment. Such information would be also useful when abnormal hand functions are evaluated.

Ultrasound guided closed reduction and pinning for adult phalangeal fractures

Objective To evaluate the value of ultrasound in adults phalangeal fractures, analysze clinical efficacy of ultrasound-assisted closed reduction and pinned fixation of adult phalangeal fracture. Methods A total of 23 phalanx fractures in 20 adult cases were recruited, including shaft fractures 4 fingers, the bottom fracture 13 fingers, and condylar fracture 6 fingers. All cases were examined by preoperative ultrasound and X-ray, intraoperative ultrasound assisted reset, and ultrasound-guided closed reduction were performed. Clinical evaluation included operative time, blooding, fluoroscopy times, the success rate of reduction inoperative, postoperative x-rays, total active motion (TAM) and grip strength. Results The postoperative follow-up ranged from 6 to 24 months, with an average of 16 months. Seventeen fingers were successful by ultrasound-guided closed reduction, and 6 fingers was reduced by C-arm fluoroscopy. The average healing time was (6.21±2.10) weeks. According to the functional evaluation criteria based on TAM, the results were rated as excellent in 14 cases (60.9%), good in 5 cases (21.7%), fair and poor in 4 cases(17.3%), the total excellent and good rates was 82.7%. Grip strength was (32.5±7.8)kg in affected side and (34.5±9.9)kg in opposite side, there was no significant difference(t=0.351, P=0.726). No nonunion occurred. Conclusions The position can be observed by ultrasound-guided percutaneous pinning of phalangeal fractures.It′s advantages are the less trauma, less blooding, and less X-ray exposure. But for some types of fractures, such as the bottom fracture and condylar fracture, the effects should be further studied. Key words: Ultrasonography; Phalangeal fractures; Fracture fixation, internal

Study on the grip spans of combination pliers in a maximum gripping task

A newly developed system was applied in this study to evaluate the effects of the grip spans (45–80 mm) of combination pliers on the total grip strength, individual finger force, resultant force, and subjective discomfort. A total of twenty-six males participated and were asked to exert their maximum grip strength with two repetitions. The highest and the lowest total grip strength and resultant force (311.8 N and 737.9 N vs. 210.1 N and 501.7 N) were obtained at a 60 mm and 80 mm grip spans, respectively. In general, the participants considered the 50 and 60 mm grip spans as being the least discomfort, whereas the 80 mm grip span was considered as the most discomfort grip span in a maximum grasping task. The results can be utilized as basic data for the manufacturing and design industries of two-handle hand tools, such as pliers and wrenches. Practitioners summaryCustom-made combination pliers were applied in this study to evaluate grip strength, resultant force, and subjective discomfort, relative to five grip spans. The authors expect that the results of the present study will provide valuable information for the designers and users of pliers.

Evaluation of pliers’ grip spans in the maximum gripping task and sub-maximum cutting task

A total of 25 males participated to investigate the effects of the grip spans of pliers on the total grip force, individual finger forces and muscle activities in the maximum gripping task and wire-cutting tasks. In the maximum gripping task, results showed that the 50-mm grip span had significantly higher total grip strength than the other grip spans. In the cutting task, the 50-mm grip span also showed significantly higher grip strength than the 65-mm and 80-mm grip spans, whereas the muscle activities showed a higher value at 80-mm grip span. The ratios of cutting force to maximum grip strength were also investigated. Ratios of 30.3%, 31.3% and 41.3% were obtained by grip spans of 50-mm, 65-mm, and 80-mm, respectively. Thus, the 50-mm grip span for pliers might be recommended to provide maximum exertion in gripping tasks, as well as lower maximum-cutting force ratios in the cutting tasks.

Fire fit: assessing comprehensive fitness and injury risk in the fire service

This study sought to develop a comprehensive measure of fitness that is predictive of injury risk and can be used in the fire service to assess individual-level health and fit-for-duty status. A retrospective occupational cohort of 799 career fire service employees was observed over the years 2005-2009. An equally weighted score for comprehensive fitness was calculated based on cardiovascular fitness, muscular strength, endurance, flexibility, and body composition. Repeated measures survival analyses were used to estimate the risk of any injury, sprain or strain, and exercise-related injuries in relation to comprehensive fitness. A well-distributed comprehensive fitness score was developed to distinguish three tiers of overall fitness status. Intraclass correlations identified flexibility, total grip strength, percent body fat, and resting heart rate as the most reliable fitness metrics, while push-ups, sit-ups, and aerobic capacity demonstrated poor reliability. In general, individuals with a lower comprehensive fitness status had an increased injury risk of injury as compared to the most fit individuals. The risk of any injury was 1.82 (95% CI 1.06-3.11) times as likely for the least fit individuals, as compared to individuals in the top fire fitness category, increasing to 2.90 (95% CI 1.48-5.66) when restricted to sprains and strains. This 5-year analysis of clinical occupational health assessments enabled the development of a relevant metric for relating comprehensive fitness with the risk of injury. Results were consistent with previous studies focused on cardiorespiratory fitness, but also less susceptible to inter-individual variability of discrete measurements.

The relationship between hand anthropometrics, total grip strength and individual finger force for various handle shapes

The design and shape of hand tool handles are critical factors for preventing musculoskeletal disorders (MSDs) caused by the use of hand tools. We explored how these factors are related to total force and individual finger force in males and females with various hand anthropometrics. Using the MFFM system, we assessed four indices of anthropometry, and measured total force and individual finger force on various handle designs and shapes. Both total force and individual finger force were significant according to gender and handle shape. Total grip strength to the handle shape indicated the greatest strength with D shape and the least with A shape. From the regression analysis of hand anthropometric indices, the value of R was respectably high at 0.608–0.696. The current study examined the gender and handle shape factors affecting grip strength based on the force measurements from various handle types, in terms of influence on different hand anthropometric indices.

Evaluation of Gender Effect in Various Pliers' Grip Spans for Maximum Isometric Grasping Tasks

Objective: The purpose of this study was to evaluate the effect of gender (male, female) and grip spans (45, 50, 60, 70, 80mm) on total grip strength, resultant force, finger force and subjective discomfort ratingI. Background: In order to prevent musculoskeletal disorders, studies of hand tools need to be preceded based on grip strength, finger force, and subjective discomfort rating. However, experimental apparatus using tools such as pliers that reflect the actual work place was almost non-existent. Method: Fifty-Two (26 males and 26 females) participants were recruited from the student population. In this study, a pair of revised pliers, which can change grip span from 45 to 80mm was applied to estimate total grip strength, resultant force and individual finger forces. All participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: There were significant differences of total grip strength, resultant force, individual finger forces and subjective discomfort rating according to grip span. The lowest total grip strength was obtained from the grip span of 80mm for both genders. For resultant force, the highest resultant force was exerted at grip spans of 50, 60 and 70mm for females and 50 and 60mm for males. The lowest subjective discomfort rating was observed in the 50mm for both genders. Conclusion: Based on the result, 50mm and 60mm grip spans which provide the highest force and lowest discomfort rating might be recommendable for the male and female pliers users. Application: The findings of this study can provide guidelines on designing a hand tool to help to reduce hand-related musculoskeletal disorders and obtain better performance.