Context:
Determining whether there are compensations in those with jumper’s knee (JK) might further our understanding of the condition.
Objective:
Comparing lower extremity kinematics and jump performance of basketball athletes with JK with those of healthy controls (C).
Design:
Repeated-measures control-match design.
Setting:
University laboratory.
Participants:
24 male basketball players (12 JK, 12 C) matched by height, weight, position, experience, and frequency of play.
Interventions:
Standing countermovement and running layup jumps.
Main Outcome Measures:
Maximum vertical-jump height, footfall landing, and lower extremity sagittal-plane kinematics.
Results:
There were no significant group differences (P > .05) in vertical-jump height (JK = 64.3 ± 8.6 cm, C = 63.0 ± 9.8 cm) or layup height (JK = 71.3 ± 11.6 cm, C = 73.3 ± 11.0 cm). JK subjects landed flat footed (50%) more than controls (8%). JK subjects showed significantly more hip flexion (JK = 105° ± 24.8°, C = 89.8° ± 14.1°; P = .039) with decreased hip acceleration during the countermovement (JK = −3039 ± 1392°/s2, C = −4229 ± 1765°/s2; P = .040). When landing from the countermovement jump, JK subjects had significantly less knee acceleration (JK = −4960 ± 1512°/s2, C = −6736 ± 2009°/s2; P = 023) and in the layup showed significantly less ankle dorsiflexion (JK = 106.5° ± 9.0°, C = 112.5° ± 7.7°; P = .048) and hip acceleration (JK = − 2841 ± 1094°/s2, C = −3912 ± 1575°/s2; P = .033).
Conclusion:
Compensatory strategies observed in JK subjects might help maintain performance, because their jump height was similar to that of healthy controls.
