Compensatory Kinetics During the Side-Hop Test in Individuals With Chronic Ankle Instability

Abstract

Context: Individuals with chronic ankle instability (CAI) exhibit altered movement strategies during side-cutting tasks. However, no researchers have assessed how altered movement strategies affect cutting performance.

Objective: To investigate compensatory strategies in the side-hop test (SHT), with a focus on the entire lower extremity, among individuals with CAI.

Design: Cross-sectional study.

Setting: Laboratory.

Patients or other participants: A total of 40 male soccer players comprising a CAI group (n = 20; age = 20.35 ± 1.15 years, height = 173.95 ± 6.07 cm, mass = 68.09 ± 6.73 kg) and a control group (n = 20; age = 20.45 ± 1.50 years, height = 172.39 ± 4.39 cm, mass = 67.16 ± 4.87 kg).

Intervention(s): Participants performed 3 successful SHT trials.

Main outcome measure(s): We calculated SHT time, torque, and torque power in the ankle, knee, and hip joints during the SHT using motion-capture cameras and force plates. Confidence intervals for each group that did not overlap by >3 points consecutively in the time series data indicated a difference between groups.

Results: Compared with the control group, the CAI group showed (1) no delayed SHT time; (2) lower ankle-inversion torque (range = 0.11-0.13 N·m/kg) and higher hip-extension (range = 0.18-0.72 N·m/kg) and -abduction torque (0.26 N·m/kg); (3) less concentric power in ankle dorsiflexion-plantar flexion (0.18 W/kg) and inversion-eversion (0.40 W/kg), more concentric power in hip flexion-extension (0.73 W/kg), and more eccentric power in knee varus-valgus (0.27 W/kg).

Conclusions: Individuals with CAI were likely to rely on hip-joint function to compensate for ankle instability and demonstrated no differences in SHT time compared with the control group. Therefore, the movement strategies of individuals with CAI could differ from those of individuals without CAI, even if SHT time is not different.

Keywords: ankle sprains; functional performance test; injury prevention; return to sport.

Figure 1

Time series data of torque and torque power in the sagittal plane in the medial-hop contact phase. A, Ankle dorsiflexion-plantar-flexion torque. B, Knee flexion-extension torque. C, Hip flexion-extension torque. D, Ankle-torque power. E, Knee-torque power. F, Hip-torque power. Gray shaded areas indicate when the 90% CIs of the groups did not overlap, representing a difference.

Figure 2

Time series data of torque and torque power in the frontal plane in the medial-hop contact phase. A, Ankle inversion-eversion torque. B, Knee varus-valgus torque. C, Hip adduction-abduction torque. D, Ankle-torque power. E, Knee-torque power. F, Hip-torque power. Gray shaded areas indicate when the 90% CIs of both groups did not overlap, representing a difference.

Figure 3

Time series data of torque and torque power in the sagittal plane in the lateral-hop contact phase. A, Ankle dorsiflexion-plantar-flexion torque. B, Knee flexion-extension torque. C, Hip flexion-extension torque. D, Ankle-torque power. E, Knee-torque power. F, Hip-torque power. Gray shaded areas indicate when the 90% CIs of both groups did not overlap, representing a difference.

Figure 4

Time series data of torque and torque power in the frontal plane in the lateral hop contact phase. A, Ankle inversion-eversion torque. B, Knee varus-valgus torque. C, Hip adduction-abduction torque. D, Ankle-torque power. E, Knee-torque power. F, Hip-torque power. Gray shaded areas indicate when the 90% CIs of both groups did not overlap, representing a difference.