INVESTIGATION OF THE RELATIONSHIP BETWEEN ANTHROPOMETRIC MEASUREMENTS AND FOREARM POSTURES WITH GRIP STRENGTH IN YOUNG ADULTS

BACKGROUND: Grip strength is widely accepted as an indicator of maximum hand strength and contraction of active muscles of the hand and forearm. OBJECTIVE: The aim of this study was to assess the effects of forearm posture (pronation, supination and neutral) and anthropometric variation on MVC grip strength and grip endurance time in young university adults. METHODS: Fifty healthy, right-handed men volunteered to participate in this study. The experiment was characterized by measuring MVC grip strength and endurance time of 50% MVC randomly in three different postures (supine, pronation and neutral). Performance was assessed in terms of dependent variables: MVC grip strength and grip endurance time. RESULTS: MANCOVA results showed no significant effect of posture on MVC grip strength ([Formula: see text]) and grip endurance time ([Formula: see text]). There was a significant effect of age ([Formula: see text]), height ([Formula: see text]) and forearm length ([Formula: see text]) on the grip endurance time in supine position. However, palm circumference had a significant effect on MVC grip strength ([Formula: see text]) in pronation posture only. The pronation forearm posture produces 7.4% more grip strength than a supine posture. In addition, the grip endurance time was improved in the supine position, compared to the neutral and pronation forearm posture. CONCLUSIONS: This study showed that the MVC grip strength is affected by the weight and palm circumference. In addition, palm circumference was the most influential factor affecting grip strength. Thus, anthropometric and posture-specific grip strength data are essential for clinical and industrial applications. The results can be used to prepare guidelines for rehabilitation, health care, sport and medicine.

The Effects of Forearm Kinesio-Taping on Hand Grip Strength and Endurance in Female Squash Elites

Background: Hand grip plays a fundamental role in most daily and athletic activities of the upper extremities. Objectives: The study compared the effect of various methods of forearm Kinesio-taping (KT) on the hand grip strength and endurance of Iranian elite squash players during their sporting activities at different times. Methods: Thirty-three female squash players were assigned to a quasi-experimental study, and KT was applied on their dominant forearm (on the flexor area, on the extensor area, and placebo taping). Grip strength was evaluated before, immediately, 30, and 60 minutes after KT, and grip endurance was also assessed before and 60 minutes after KT using MIE digital grip analyzer. Friedman and Kruskal-Wallis tests were used to analyze the results of grip strength, and ANOVA and the sample t-test were applied to analyze the grip endurance data. Results: The findings revealed no significant differences within the grip strength at different phases (P > 0.05). However, p values for the outcomes of KT on the flexor area‎, KT on the extensor area‎, and placebo mode were respectively 0.145, 0.178, 0.065 in each phase of the evaluation. A significant difference ‎among KT groups and the LSD test revealed a significant increase in grip endurance in the mode of KT on the extensor area, whereas there have been no significant differences in grip endurance in KT on flexor (P = 0.785) and extensor (P = 0.457) areas. Conclusions: There was no obvious superiority of the various methods of forearm ‎ KT ‎ on grip strength at different times; nevertheless, KT was an efficient method for retaining grip endurance in squash players with no significant differences between the flexor and extensor locations.

Evidence for a Behaviourally Measurable Perseverance Trait in Humans

The aim was to create and study a possible behavioural measure for trait(s) in humans that reflect the ability and motivation to continue an unpleasant behaviour, i.e., behavioural perseverance or persistence (BP). We utilised six different tasks with 54 subjects to measure the possible BP trait(s): cold pressor task, hand grip endurance task, impossible anagram task, impossible verbal reasoning task, thread and needle task, and boring video task. The task performances formed two BP factors. Together, the two-factor solution is responsible for the common variance constituting 37.3% of the total variance in the performances i.e., performance times. Excluding the impossible anagram task, the performance in any given task was better explained by performances in the other tasks (i.e., “trait”, η2 range = 0.131–0.253) than by the rank order variable (“depletion”, i.e., getting tired from the previous tasks, η2 range = 0–0.096).

Effects of vibratory massage therapy on grip strength, endurance time and forearm muscle performance

BACKGROUND: Vibration therapy (VT) causes an increase in motor unit activation tendency, an involuntary recruitment of earlier sedentary motor units, which increases the muscle fiber force generating capacity and muscle performance. OBJECTIVE: To evaluate the effect of vibratory massage therapy at 23 Hz and 35 Hz on grip strength, endurance, and forearm muscle performance (in terms of EMG activity). METHODS: Ten healthy and right-handed men participated voluntarily in this study. The experiment was characterized by the measurement of MVC (maximal voluntary contraction) grip strength and grip endurance time at 50%MVC, accompanied by the corresponding measurement of the EMG signals of the muscles viz., flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi radialis brevis (ECRB); and extensor carpi ulnaris (ECU) in supine posture. RESULTS: MANCOVA results showed significant effects of VT frequency on endurance time (p < 0.001); but no significant effect on the grip strength (p = 0.161) and muscle performance (in terms of EMG activities of the forearm muscles). However, VT improves the MVC grip strength and grip endurance time (better at 35 Hz). The Pearson correlation was significant between: weight, palm length, palm circumference, and forearm length with MVC grip strength; and the palm length with the endurance time. In addition, the palm length, palm circumference, and forearm circumference generally serve to better predict MVC grip strength and grip endurance time. CONCLUSIONS: Vibration therapy at 35 Hz for 10 minutes on the forearms had a significant positive effect on the neuromuscular performance to enhance muscle performance of upper extermitites and can be used as the optimal range to study the effect of VT. Findings may be used to prepare guidelines for VT in rehabilitation, healthcare, sports, and medical for therapists.

Electromyography-based Fatigue Assessment During Endurance Testing by Different Vibration Training Protocols

Objectives: This study presents a method of assessing muscle fatigue during endurance testing at 50% maximal voluntary contraction (MVC) using electromyography (EMG) information as indirect indices of fatigability in the forearm muscles, namely, flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi ulnaris (ECU) and extensor carpi radialis brevis (ECRB)." This study presents a method of assessing muscle fatigue during endurance testing at 50% maximal voluntary contraction (MVC) using electromyography (EMG) information as indirect indices of fatigability in the forearm muscles, namely, flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi ulnaris (ECU) and extensor carpi radialis brevis (ECRB). Methods: A randomized comparative experimental design was used during endurance test with 8 VT protocols; based on different combinations of vibration frequency (35 & 45 Hz), amplitude (3±0.5g & 9±0.5g), and exposure duration (30 & 60 seconds), i.e., were given to the study participants for 4 days. A random sampling of participants was conducted from two groups (n=56/group), as follows: individuals with a Sedentary Lifestyle (SL) and a group of Construction Workers (CW). Results: Multivariate Analysis of Variance (MANOVA) results indicated a significant increase in EMG rms, median frequency, waveform length, mean absolute value (P<0.001), and the variance of EMG signal (P<0.05) (except in ECU for the SL group and ECRB for the CW group on the variance of EMG signal) after VT in all muscles of both research groups. Therefore, an increase in the EMG parameter value after a grip endurance task revealing an elevation in EMG signal amplitude is indicative of muscle fiber fatigue. Furthermore, the strongest correlation was found between grip endurance and WL (r=0.471, P<0.001), and EMG rms (r=0.401, P<0.001) of the ECU muscle in the SL group only. Discussion: The patterns of EMG signal represented the amplitude and spectral parameters of the signal, enabling real-time fatigue analysis. Additionally, surface EMG information is useful for indirectly evaluating performance fatigue during the endurance test.

AB1287-HPR INVESTIGATION OF THE RELATIONSHIP BETWEEN GRIP ENDURANCE, DISABILITY OF UPPER EXTREMITY AND QUALITY OF LIFE IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:Upper extremity functions affect the quality of life at different levels in patients with rheumatoid arthritis (RA). In the current literature; it has been shown that grip endurance is associated with upper limb functions (1). However, there is no study investigating the relationship between grip endurance and quality of life in patients with RA.Objectives:To investigate relationship between grip endurance, disability of upper extremity and quality of life in patients with RA.Methods:In our cross sectional study, 23 RA patients [Mean age; 52.7±12.6, BMI;26.9±5.7 kg/m2, Women;20(87.0%)] who were classified according to the ACR 2010 criteria. Demographics and clinical characteristics of patients were recorded (Table 1). Das28 for disease activity score, Static and dynamic grip endurance measurements using Hand Dynamometer (Lafayette Proffessional Hand Dynamometer, USA) for grip endurance, Disability of Arm, Shoulder and Hand Survey (DASH) for disabilities and symptoms of upper extremity and Short Form-36 Health Survey for quality of life were performed. Spearman’s Rank Correlation Coefficient was used for data analysis.Table 1.Demografic and Clinical Characteristics of PatientsVariables (n=23)Median(IQR 25/75)Age (year)56(41/62)BMI (kg/m2)27,5(21.4/32.0)Disease Duration(year)8(5/15)Morning Stiffness (VAS/mm)38(23/48)Perceived Disability of Hand (VAS,mm)47(25/67)Clinician Disability of Hand (VAS,mm)30(20/39)Number Of Tender Hand Joint2(0/6)Number Of Swollen Hand Joint0(0/1)CRP(mg l)3,3(1.8/7.1)ESR(nm/h)13(6/21)n(%)Morning Stiffness Duratton0-15 minutes8 (34.8)15-30 minutes5 (21.7)30-60 minutes3 (13.0)Longer than 1 hours7 (30.4)Das28Remission11(47.8)Low Activity2(8.7)Moderate Activity7(30.4)High Activity3(13.0)Data is presented median (interquantile range) or percentile (%).Results:Grip endurance was negatively correlated with DASH and positively correlated with many different quality of life parameters, especially physical function, on both the dominant and non-dominant sides (p <0.05). DASH was correlated negatively with SF-36 physical function, rol limitataion due to physical health, pain subparameters and positively correlated with Das28 score (p<0.05).Conclusion:In our study, it was concluded that grip endurance was related to upper extremity functions and quality of life in patients with RA. This result shows that; assessment of grip endurance can be a guide for clinicians who have designed an upper limb rehabilitation program for patients with RA.References:1. VERMA, Chhaya, et al. Correlation of functional ability of the hand with upper limb function and quality of life in patients with rheumatoid arthritis.J Assoc Physicians India, 2017, 65: 20-4.Disclosure of Interests:None declared

Comparison of the Effects of Three Hangboard Strength and Endurance Training Programs on Grip Endurance in Sport Climbers

Intermittent isometric endurance of the forearm flexors is a determinant factor of sport climbing performance. However, little is known about the best method to improve grip endurance in sport climbing regarding maximal or intermittent dead-hang training methods. The aim of this study was to compare the effects of three 8-week finger training programs using dead-hangs (maximal, intermittent, and a combination) on grip endurance. Twenty-six advanced sport climbers (7c+/8a mean climbing ability) were randomly distributed among three groups: maximal dead-hangs with maximal added weight on an 18 mm edge followed by MaxHangs on minimal edge depth; intermittent dead-hangs using the minimal edge depth, and a combination of both. The grip endurance gains and effect size were 34% and 0.6, respectively, for the group following maximal dead-hang training, 45% and 1, respectively, for the group following intermittent dead-hang training, and 7% and 0.1, respectively, for the group applying the combination of both training methods. Grip endurance increased significantly after 4 weeks in the group performing intermittent dead-hangs (p = 0.004) and after 8 weeks in both groups performing intermittent dead-hangs (p = 0.002) and MaxHangs (p = 0.010). The results suggest that the intermittent dead-hangs training method seems to be more effective for grip endurance development after eight week application in advanced sport-climbers. However, both methods, maximal and intermittent dead-hangs, could be alternated for longer training periods