“At-Risk” Positioning and Hip Biomechanics of the Peewee Ice Hockey Sprint Start

Background Femoroacetabular impingement (FAI) is becoming a prevalent overuse injury diagnosis among hockey players. In the adult ice hockey stride, the “at-risk” hip position, defined by internal rotation during flexion and external rotation during abduction, reportedly increases hip vulnerability to labral injury as a result of FAI. Hypothesis Peewee youth ice hockey players display the kinematics for both described at-risk hip positions (internal rotation during flexion and external rotation during abduction) in the ice hockey sprint start. Study Design Descriptive laboratory study. Methods Twelve healthy male Peewee ice hockey players (mean age, 10.8 ± 0.6 years) participated in this study. Thirty-five anatomic landmarks were used to analyze the 3-dimensional kinematic and kinetic variables of the hip associated with the ice hockey sprint start. Ten high-speed (120-Hz) infrared cameras recorded the trials, which were subsequently analyzed with Motion Monitor software. The sprint start was recorded over 4 defined periods of motion: start, push, swing, and even. Results In the “push” period, 11.5° of external rotation was observed concurrently with 13.2° of abduction in the push leg, and 6.8° of internal rotation occurred with 33.8° of flexion in the lead leg. During the recovery phase of the “swing” period, maximum internal rotation was 5.6° with concurrent hip flexion of 44.2° in the push leg, while lead leg internal rotation reached a maximum of 10.8° with hip flexion of 35.1° during the “even” period. Conclusion During the sprint start, youth ice hockey players externally rotate in abduction during the push-off phase and internally rotate through increasing hip flexion during the recovery phase, displaying the at-risk hip positions of the ice hockey skating stride. Clinical Relevance During the sprint start, youth ice hockey players position their hips in a manner that can cause impingement of the femoral neck against the acetabulum and potentially lead to labral tears and/or articular cartilage damage. This knowledge could be applied to assist in the prevention of overuse injuries of the hip as youth hockey players mature and increase in skill level.