The Relationship between Core Stability Related Measurements and Countermovement Jump Height with/without Arm Swing

Objective: To detect the relationship between core stability related measurements (CSRM) and countermovement jump (CMJ) performance with/without arm swing (AS) . Methods: 20 active college students were recruited from local university. CMJ height with AS (HAS) and without AS (HNAS) were calculated from vertical ground reaction force data collected using a force platform. The CMJ height was calculated according to the Mechanical Energy Conservation. CSRM included 5 tests: trunk flexion (TF) and extension (TE) , where total range of motion (TFE) can be calculated; dominant limb single leg stance time test (DLS) ; dominant limb single leg hop distance test (DLH) ; timed sit-up test (SU) ; and trunk extensor endurance test (EE) . Pearson correlation coefficient was employed to detect the correlation between CMJ height and CSRM. Linear Regression was conducted to determine which independent variables in CSRM were significant predictors of CMJ performance. Results: DLH correlated with HNAS significantly, the two variables shared 45.3% variance. DLH correlated with HASsignificantly, they shared 46.5% variance. The difference (DFE) between TF and TE correlated significantly with the difference (DAN) between HAS and HNAS, and they shared 34.0% variance. Conclusion: DLH is a good predictor for both HNAS and HAS. DFE is a good predictor for DAN. Greater trunk flexion range of motion, combined with less trunk extension range of motion could be the key to understand how AS helps to improve CMJ height.