Kinetic Factors Related to the Side Hop Test Time in Healthy Individuals

The side hop test (SHT) has been proven to be a highly valid assessment tool for the ankle joint. However, previous studies have not revealed which joints affect the SHT time. Thus, interpreting the SHT time correctly may be challenging. Investigating factors that determine the SHT time would provide important basic information regarding the SHT. Therefore, we aimed to investigate the kinetic factors related to the SHT time in healthy individuals. Twenty healthy male college soccer players formed our study population. Three-dimensional motion analysis was conducted during the SHT. The SHT time and peak torque power (hip, knee, and ankle) during the medial hop (MC) and lateral hop contact (LC) phases in the SHT were calculated. The relationship between the SHT time and peak torque power was examined using Pearson's correlation coefficient. In terms of concentric power, significant negative correlations were found between the SHT time and peak concentric hip power in the sagittal (r = -0.77 to -0.67) and frontal planes (r = -0.74 to -0.47) in each phase. For eccentric power, significant positive correlations were found between the SHT time and peak eccentric ankle power in the sagittal plane (r = 0.48-0.50) in each phase. In addition, significant positive correlations were found between the SHT time and peak eccentric hip power in the frontal plane (r = 0.55) in MC, peak eccentric hip power in the sagittal plane (r = 0.63), and eccentric ankle power in the frontal plane (r = 0.52) in LC. Our results showed that concentric and eccentric power were important for the hip and ankle joints, respectively, and different functional requirements depended on the joint. Based on these findings, clinicians can use the SHT to assess an athlete's condition and appropriately determine their safe return to sports.