RELATIONSHIPS BETWEEN HAND AND FINGER MUSCLE STRENGTH AND TAPPING ABILITY AMONG WORKERS DURING USING GRINDERS

Abstract

Analyses of psychomotor changes before and during grinding work of thirty female workers performing a grinding operation with another thirty female office workers as the control group. Hand muscle strength was measured by assessing hand grip strength (HGS) and pinch strength (PS) while hand dexterity was measured by the maximum tapping ability in 10 seconds (MTA). The  participants were asked to perform the tests at (1) initial time at 08.00 a.m., (2) before morning rest break at 10.00 a.m., (3) after morning rest break at 10.10 a.m., (4) before lunch at 12.00 a.m., (5) after lunch at 13.00 p.m., (6) before afternoon rest break at 15.00 p.m., (7) after afternoon rest break at 15.10 p.m. and (8) end of work at 17.00 p.m.. In contrast, the control office worker group was measured only at before work (08.00 a.m.). The result showed that the HGS, PS and MTA of the dominant hand were generally stronger than those of the non-dominant hand (p-value <0.05). Several pairs of raw data of the above parameters were computed by SPSS Inc. (2001 program) to find the significant level (p) and correlation coefficients (r). It was found that the MTA was significantly correlated with PS and HGS (r = 0.249 and 0.308, p-value <0.001, respectively). PS and HGS were significantly correlated (r = 0.708, p-value < 0.001). This may show that all tests confirmed the changes of hand strength and dexterity after prolonged grinder using. The result shows that after the workers were exposed to vibration from the grinding process, they were affected by decreased hand muscle strength and decreased hand maximal tapping ability with relatively linear proportion.

(Journal of Sports Science and Technology  2012; 12 (2): 9 - 15)