Effects of Anterior Knee Displacement During Squatting on Patellofemoral Joint Stress

• Published in: Journal of sport rehabilitation Vol. 27; no. 3; p. 237
• Main Authors: Kernozek, Thomas W, Gheidi, Naghmeh, Zellmer, Matthew, Hove, Jordan, Heinert, Becky L, Torry, Michael R
• Format: Journal Article
• Language: English
• Published: United States 01.05.2018
• Subjects: Ankle Joint - physiology; Biomechanical Phenomena; Exercise Therapy; Female; Hip Joint - physiology; Humans; Patellofemoral Joint - physiology; Patellofemoral Pain Syndrome - rehabilitation; Range of Motion, Articular; Young Adult; kinematics; rehabilitation; kinetics; knee joint
• ISSN: 1543-3072
• DOI: 10.1123/jsr.2016-0197

Squatting is a common rehabilitation training exercise for patellofemoral pain syndrome (PFPS). Patellofemoral joint stress (PFJS) during squatting with more anterior knee displacement has not been systematically investigated. To compare PFJS during squatting using 2 techniques: squat while keeping the knees behind the toes (SBT) and squat while allowing the knees to go past the toes (SPT). University research laboratory. Twenty-five healthy females (age: 22.69 (0.74) y; height: 169.39 (6.44) cm; mass: 61.55 (9.74) kg) participated. Three-dimensional kinematic and kinetic data were collected at 180 and 1800 Hz, respectively. A musculoskeletal model was used to calculate muscle forces through static optimization. These muscle forces were used in a patellofemoral joint model to estimate PFJS. The magnitudes of PFJS, reaction force, and quadriceps force were higher (P < .001) during SPT compared with the SBT technique. Knee flexion, hip flexion, and ankle dorsiflexion angles were reduced when using the SBT technique. Findings provide some general support for minimizing forward knee translation during squats for patients that may have patellofemoral pain syndrome.