Abstract
Purpose: The main aim of this study was to assess bilateral isokinetic peak torque (PTQ) in the knee and shoulder joint of university rowers. A secondary aim was to examine possible bilateral muscle imbalances and to compare the males to the females in terms of PTQ produced. Method: The research design was a descriptive, quantitative study. The population of the research were university rowers in Gauteng. The research sample included rowers that were part of a university rowing club in Gauteng (n=37). Sampling included male and female rowers ranging between the ages of 18 and 35 years. All participants who consented to participate completed a PAR-Q and a comprehensive medical history questionnaire. Knee flexion and extension, shoulder internal (IR) and external rotation (ER) were assessed using the Humac Norm Isokinetic Dynamometer at 60°/sec, using a concentric-concentric (CON-CON) and eccentric-eccentric (ECC-ECC) contraction mode. Descriptive statistics (means, minimums, maximums and standard deviations) and non-parametric comparative statistics (Mann-Whitney U Test) were used to analyse the data. Statistical significance was set at p<0.05. Results: Participants included 24 males (21.58 ±2.08 y) and 13 females (21.77 ±2.28 y). Significant differences were found between the dominant (DL) and non-dominant (NDL) CON and ECC knee extension PTQ at 60°/sec in male rowers (DL>NDL), but not in female rowers. However, in female rowers there were significant differences between the DL and the NDL for the eccentric hamstring/quadriceps (ECC H/Q) ratio and for CON and ECC shoulder IR and ER at 60°/sec (NDL>DL).A significant difference was also found for male rowers in CON PTQ for shoulder ER (DL>NDL), and ECC PTQ IR at 60°/sec (DL>NDL). Both CON knee H/Q ratio and CON shoulder ER/IR ratio at 60°/sec had no significant difference in DL and NDL for males and females (p≥0.05). However, there were significant differences in the DL and NDL for ECC knee H/Q ratio at 60°/sec for female rowers (NDL>DL; p=0.019), as well as for ECC shoulder ER/IR ratio for male rowers (NDL>DL; p=0.003). There was also a significant difference observed between males and females for the DL shoulder ER/IR ratio (p=0.002). Conclusion: The present study is the first to establish isokinetic reference values for the knee and shoulder muscles in South African university rowers. In addition, the results highlight the presence of significant muscle imbalances in both male and female rowers for CON and ECC knee flexion and extension, as well as for shoulder IR and ER.
M.Phil. (Biokinetics)