The analysing of hand grip strength of healthy people in different positions of upper extremities

The primary aim of this study was to determine the effect of various shoulder positions on grip strength. The other aims were to analyse the correlation between grip strength and occupational and anthropometric characteristics of the people. The data obtained from 113 females aged 20-30 years and employed in four different occupations (teacher, worker, nurse and student) were analysed. Jamar Hydraulic Dynamometer was used for grip strength measurements. Besides the assessment in standard test position, the grip strength was also measured in shoulder flexion and abduction at 0º, 45º, 90º and 135°. In all positions of the shoulder, elbow was positioned in full extension while forearm was positioned in semipronation. Body weight, height and other anthropometric characteristics of the study subjects were measured and recorded. The grip strength results and anthropometric measures of study subjects were presented in groups and dominant hand was used as a reference. Paired Samples t Test was used in order to find if there is a difference in grip strength between dominant and non dominant hands. Pearson correlation analysis was used to determine the significance of relationship between anthropometric measurements and grip strength. In order to find the factors having effects grip strength, Stepwise Multiple Regression analysis was used. For evaluation the effect of shoulder position and occupations on grip strength, Repeated Measures ANOVA was utilized. In result, a significant difference for grip strength in different shoulder positions was not found in all groups and also for each occupation. For all the study subjects, the grip strength was found approximately 10% more in the dominant hand comparing to nondominant hand. A significant difference was not found between grip strengths in shoulder flexion and abduction at the same range of motions (p?0,01). The correlation between grip strength and anthropometrics was found as positive. Hand width appeared as the most effective factor for the level of grip strength (r=0,333; p?0,01). In conclusion, the maximum grip strength was found to be not affected from shoulder position and, this finding was also valid for the occupations having different workloads.