Lower Extremity Strength, Kinematics, and Activation During a Drop Vertical Jump in Individuals With and Without Patellofemoral Pain

• Published in: Journal of athletic training 2017-06, Vol.52 (6), p.S133
• Main Authors: Baellow, A, Glaviano, N R, Hertel, J, Saliba, S A
• Format: Article
• Language: English
• Subjects: Biomechanics; Control Groups; Electromyography; Females; Jumping; Kinematics; Kinetics; Knee; Outcome Measures; Pain
• ISSN: 1062-6050; 1938-162X

An abstract of the study by Baellow determining how lower extremity range of motion (ROM), strength, surface electromyography (EMG), kinematics and kinetics, and self-reported pain-function differ between females suffering from PFP and healthy females during a drop vertical jump (DVJ). Results show that a statistically significant difference was identified in subjective function AKPS (Healthy: 100 ± 0, PFP: 74.57 ± 7.89, p < 0.001) and ADLS (Healthy: 99.8 ± 0.77, PFP: 77.67 ± 9.66, p < 0.001) and in both current pain (Healthy: 0 ± 0, PFP 1.62 ± 1.78, P = 0.001) and pain during the DVJ: (Healthy: 0 ± 0, PFP: 2.29 ± 2.05, p < 0.001). PFP patients were significantly weaker than the healthy controls in both hip abduction and hip external rotation and had a significant decrease in hamstring and IT band flexibility. A statistically significant difference in muscle activity was found in the VMO (Healthy: 120.84 ± 80.73, PFP: 235.84 ± 152.29, p lt; 0.05) with a large effect size (d = 0.94, 95% CI (0.19, 1.7). A significant difference was seen in frontal plane kinematics, as those in the PFP group had greater excursion of hip adduction (d = 0.78, 95% CI (0.04, 1.52) during the DVJ (Healthy: 3.95 ± 4.76°, PFP: 9.90 ± 9.65°, p = 0.041). A relationship was identified between subjective and objective function as VAS had a moderate relationship with knee rotation excursion (r = 0.608, p = 0.016). Knee rotation excursion also had a moderate relationship with hip external rotation strength (r = -0.541, p = 0.037) in the PFP group.