The influence of muscle group location and race on the relationship between muscle strength and power

Objective. This study investigated the influence of muscle group location and racial background on the relationship between measures of muscle strength and power, It was hypothesized that both African American (AA) and Caucasian American (CA) males would exhibit similar strength-power relationships, but these relationships would be dependent upon muscle group location. Experimental design. A cross-sectional, comparative design was used, Setting, The Human Performance Laboratory at the U. of Oklahoma. Subjects. Normal, healthy college-aged AA (n=14) and CA (n=15) males volunteered for this study. Measures. Upper and lower body strength (IRM) was assessed using a Smithpress bench press and Polaris leg press, and upper and lower body power was measured with a piezoresistive accelerometer. Results. When comparing power between upper and lower body muscle groups, both AA and CA groups exhibited similar relationships (r=0.68 and r=0.61, respectively), however, the relationship between upper and lower body strength was relatively stronger for the AA group (r=0.65 vs r=0.42). When evaluating the strength-power relationship within a given muscle group, i.e., upper or lower body, there were no racial differences, but the relationship between strength and power did differ with respect to muscle group location. Conclusions. There were stronger relationships between measures of muscular strength and power for the lower limbs when compared to the upper body indicating the importance of muscle group location rather than racial ethnicity as a confounding factor that can affect neuromuscular force production, This information is important when attempting to characterize neuromuscular function relative to specific skills or motor sport performance, thus emphasizing the principle of specificity.