Adaptations in single-leg hop biomechanics following anterior cruciate ligament reconstruction

Abstract

When a patient performs a clinically normal hop test based on distance, it cannot be assumed that the biomechanics are similar between limbs. The objective was to compare takeoff and landing biomechanics between legs in patients who have undergone anterior cruciate ligament reconstruction. Kinematics and ground reaction forces were recorded as 13 patients performed the single-leg hop on each leg. Distance hopped, joint range of motion, peak joint kinetics and the peak total extensor moment were compared between legs during both takeoff and landing. Average hop distance ratio (involved/noninvolved) was 93 ± 4%. Compared to the noninvolved side, knee motion during takeoff on the involved side was significantly reduced (P = 0.008). Peak moments and powers on the involved side were lower at the knee and higher at the ankle and hip compared with the noninvolved side (Side by Joint P = 0.011; P = 0.003, respectively). The peak total extensor moment was not different between legs (P = 0.305) despite a decrease in knee moment and increases in ankle and hip moments (Side by Joint P = 0.015). During landing, knee motion was reduced (P = 0.043), and peak power absorbed was decreased at the knee and hip and increased at the ankle on the involved side compared to the noninvolved side (P = 0.003). The compensations by other joints may indicate protective adaptations to avoid overloading the reconstructed knee.

Knee Biomechanics during Side-Step Cutting and Performance on Return to Sport Tests: Retrospective Analysis Following Anterior Cruciate Ligament Re- Injury

“…While they found that a specific biomechanical profile, including increased frontal plane knee motion and increased hip transverse plane moments, predicted a second ACL injury, there was no information provided as to performance on specific RTS tests. Another study by Orishimo and colleagues (2010) reported that individuals who had been cleared for return to sport following ACLR demonstrated altered lower extremity biomechanics during both the take-off and landing of a single leg hop for distance, despite a clinically acceptable performance on the test, however the incidence of re-injury following return to sport participation was not reported [12]. Future studies are needed that evaluate both performance on RTS tests, lower extremity biomechanics, and reinjury events.…”

“…However, more recent guidelines suggest that performance on RTS tests must be at least 90% that of the un-involved extremity. Examples of RTS tests commonly implemented include the 5-jump test, single leg hop for distance, triple hop for distance, single leg cross over hop for distance, single leg 6 meter hop for time, or some combination of these tests [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Assessment of Knee Kinetic Symmetry Using Force Plate Technology

“…We also wanted to supplement the work conducted by Dai et al 6 by exploring the relationship between GRF symmetry and knee power symmetry, as analysis of joint power provides insight into energy absorption during landing. 4 A significant limitation of this study is that subjects did not have a history of ACL reconstruction, which limits our ability to generalize to this population. In addition, a relatively small sample was included.…”

“…3,4 The typical pattern of asymmetry is for the uninjured knee to experience greater loading compared to the knee that underwent the ACL reconstruction. Persistent asymmetry in knee kinetics may place the athletes at risk for a second ACL injury.…”

Asymmetrical Lower Extremity Loading After ACL Reconstruction: More Than Meets the Eye

“…Compared to the nonsurgical side, the internal knee extensor moment on the surgical side is lower during squatting, 24 a lateral stepdown manuever, 7 stair climbing, 14 and single-leg hopping or jumping. 7,20,26 The surgical side, as compared to the nonsurgical side, also displays a lower vertical force during squatting 4,17 and the landing and take-off phases of a drop vertical jump, 21 and a higher vertical force in the landing phase of a single-leg hop. 26 Finally, the loading rate on the surgical side is lower than that of the nonsurgical side when landing from a drop vertical jump.…”