Background: Hamstring strain injury (HSI) is the most common cause of missing practices and sporting events among running-related athletes. The incidence rate of recurrence in individuals with HSI ranges from 12% to 63%. While various risk factors for HSI have been identified, the alterations and role of biomechanical factors as potential causes of injury have been largely overlooked. Objectives: To report the critical biomechanical parameters assessed among running-related athletes with a recurrent HSI and to present common testing protocols in assessing the biomechanical parameters among running-related athletes with a recurrent HSI. Methods: Eligibility Criteria: Included studies investigated biomechanical parameters assessed among collegiate or elite running-related athletes with recurrent HSI. Sources of Evidence: This scoping review was registered in OSF and was conducted based on PRISMA-ScR. Six electronic databases were systematically searched from 1993 to May 2022. Charting Methods: The reviewers created a data charting tool for the scoping review. Results: Out of 874 articles, a total of 10 articles were included in the scoping review. The critical biomechanical parameters assessed include trunk flexion, hip flexion, and knee extension angles (kinematic variables), flight and stance times and velocity (spatiotemporal variables), and EMG activity of biceps femoris, semitendinosus, semimembranosus, vastus lateralis, and rectus femoris, knee flexion and extension angle peak joint torque (kinetic variables). The most common running test protocols used were the 30-meter overground repeated sprint test, a percentage of maximum running velocity (treadmill), and repeated sprints on a non-motorized treadmill. The most common protocols for isokinetic muscle testing were 60 degrees (concentric), 300 degrees (concentric), and 180 degrees (eccentric) per second angular velocities. Conclusion The review demonstrated a need for more research on this topic, leading to only limited biomechanical parameters being discussed in the literature. This underscores the need for more rigorous research that could have practical applications for athletes and coaches.
Biomechanical Phenomena ; Athletes

BACKGROUND: Muscular imbalance in the core and hip is one of the major risk factors associated with PFPS. There is evidence that decreased strength of the hip musculature is present in individuals with PFPS. This decrease in hip strength can also affect the stability of the core and further predisposes an athlete to injury. OBJECTIVES: This is a cross-sectional study that compares the hip muscle strength and core stability of collegiate football players with and without PFPS. METHODS: 25 participants (10 with PFPS and 15 without PFPS) participated in the study. Hip strength was measured using a digital handheld dynamometer. Core stability was assessed through the McGill Core Strength test and the 8-stage stability test. RESULTS: The hip adductors showed to be significantly weaker in those with PFPS as compared to those without PFPS ( p=0.040). No differences were found in the hip flexor (p=0.812), hip extensor (p=0.460) and abductors (p=0.126) strength while the core musculature showed that there is a statistically significant difference on the endurance of the lateral core musculature (p<0.001) and trunk flexors (p=0.027) between the two groups. CONCLUSION Football athletes without PFPS in this study demonstrated greater core stability and hip adductor muscle strength compared to those without PFPS.
Patellofemoral Pain Syndrome ; Lower Extremity ; Football