Effect of work glove and type of muscle action on grip fatigue

Fatigue plays a major role in limiting work performance. The objectives of this study were: (1) to determine the effect of wearing a work glove on handgrip fatigue; (2) to compare the effect of a sustained grip contraction of concentric versus eccentric nature, named in this study isometric and eccentric; and (3) to determine if there is a relationship between physiological muscle performance and subjective perceptional fatigue during isometric and eccentric gripping. The study had 2 x 2 repeated measures design. The two factors were: (1) glove condition (glove, no glove); and (2) type of contraction (eccentric and isometric). The measurements taken were: (1) time to limit of endurance (T(lim)); (2) rate of perceived effort (RPE); (3) mean power frequency (MPF) derived from the electromyogram (EMG); and (4) the fatigue objective-subjective relationship (FOSR, which is the correlation coefficient between RPE and MPF). Twenty-one normal subjects maintained a handgrip of 60% of their maximal effort until exhaustion for each of the four conditions. During each trial EMG values were recorded every 5 s and RPE values were recorded every 10 s. The RPE was recorded as a subjective value selected from a l0-point Borg scale. The results showed that T(lim) was greater for the no glove condition (p < 0.0005) and for the eccentric muscle action (p < 0.05). The FOSR was greatest for the glove condition (p < 0.03) and for the isometric muscle action (p < 0.013). The MPF decline showed no significant difference for any condition. These data indicate that glove condition and type of handgrip contraction have an effect on physiological fatigue and subjective perception of fatigue.