Abstract
Objective: Movement assymetry is considered a potential risk factor for musculoskeletal injury in sport. Sports such as volleyball are thought to cause movement assymetries due to specific sporting demands. Further, between limb comparisons are often used for return to sport decisions. Despite this, little information is available regarding the presence of assymetry in volleyball athletes. Therefore the purpose of this investigation was to determine the presence of assymetry in dorsiflexion range of motion (DFROM) and dynamic postural control variables, factors important in return to sport decisions, both the group and individual level in professional male volleyball players. Secondarly, we aimed to better understand the role of DFROM on the Star excursion balance test (SEBT), a measure of dynamic postural control.
Method: Thirty-two Professional male volleyball players (age: 24.7±5.53 years, height: 190.6±7.63 cm., weight: 84.5±9.28 kg., BMI: 23.22±1.62 kg/m2) participated in this investigation. All participants reported for a single test session during which DFROM and the SEBT were assessed on both limbs.
Results: There was a significant group difference (p <0.05) between limbs for the normalized anterior (landing leg: 73.3 ± 6.2%; non-landing leg: 71.4 ± 6.8% ) posteromedial (landing leg: 112.6±9.3%; non-landing leg: 107.6±10.8%) and posterolateral (landing leg: 114.5±8.1%; non-landing leg: 111.4±9.4%) SEBT reach direction. The anterior and posteriomedial but not the posteriolateral reach differences exceeded the minimal detectable change score for the SEBT. At the individual level, the vast majority of participants demonstrated minimal assymetry. Significant correlations were found between DFROM and the anterior SEBT reach (r = 0.36 to 0.39, p<0.04) as well as the posteriolateral SEBT reach (r= 0.47 to 0.50, p<0.01).
Conclusions: Professional volleyball players do not have DFROM or dynamic postural control assymetries but DFROM can influence dynamic postural control.