Knee Joint Kinematics and Kinetics During a Lateral False-Step Maneuver
Grace M. Golden, PhD, ATC, CSCS*; Michael J. Pavol, PhDÀ; Mark A. Hoffman, PhD, ATCÀ
*University of California, Los Angeles, CA; 3Oregon State University, Corvallis, OR. Dr Golden isnow at the University of Oregon, Eugene, OR.
Context: Cutting maneuvers have been implicated as a mechanism of noncontact anterior cruciate ligament (ACL) injuries in collegiate female basketball players. Objective: To investigate knee kinematics and kinetics during running when the width of a single step, relative to the path of travel, was manipulated, a lateral false-step maneuver. Design:Crossover design. Setting: University biomechanics laboratory. Patients or Other Participants: Thirteen female collegiate basketball athletes (age 5 19.7 6 1.1 years, height 5 172.3 6 8.3 cm, mass 5 71.8 6 8.7 kg). Intervention(s): Three conditions: normal straight-ahead running, lateral false step of width 20% of body height, and lateral false step of width 35% of body height. Main OutcomeMeasure(s): Peak angles and internal moments for knee flexion, extension, abduction, adduction, internal rotation, and external rotation. Results: Differences were noted among conditions in peak knee angles (flexion [P , .01], extension [P 5 .02], abduction [P , .01], and internal rotation [P , .01]) and peak internal knee moments (abduction [P , .01], adduction [P , .01], and internal rotation [P 5.03]). The lateral false step of width 35% of body height was associated with larger peak flexion, abduction, and internal rotation angles and larger peak abduction, adduction, and internal rotation moments than normal running. Peak flexion and internal rotation angles were also larger for the lateral false step of width 20% of body height than for normal running, whereas peak extension angle wassmaller. Peak internal rotation angle increased progressively with increasing step width. Conclusions: Performing a lateral false-step maneuver resulted in changes in knee kinematics and kinetics compared with normal running. The differences observed for lateral false steps were consistent with proposed mechanisms of ACL loading, suggesting that lateral false steps represent a hitherto neglectedmechanism of noncontact ACL injury. Key Words: noncontact injury mechanisms, anterior cruciate ligament, sidestep cutting
N In collegiate female basketball players, lateral false-step maneuvers were associated with greater peak flexion, abduction, N N
and internal rotation angles; greater peak abduction, adduction, and internal rotation moments; and greater between-trials variabilityin angles and moments at the knee. Peak knee abduction angles, internal rotation angles, and adduction moments were greater for a wider lateral false step. Similar to sidestep cutting, a lateral false step during running may also place the anterior cruciate ligament at risk of injury; the risk may rise as step width increases.
he incidence of anterior cruciate ligament (ACL) injuries isconsiderable in comparison with other knee injuries.1,2 The possible need for surgical reconstruction to restore knee stability, substantial time lost from athletic participation, and long-term consequences of osteoarthritis after ACL injury substantiate the importance of determining which factors contribute to this injury.3,4 Of particular interest are the well-documented greater ACL injury rates inwomen than in men in matched sporting activities, such as soccer and basketball.1,2,5 Noncontact injury mechanisms account for 70% to 78% of all ACL ruptures in the athletic population.6,7 The primary mechanism of noncontact injury is a rapid deceleration, typically associated with a double-leg or single-leg landing from a jump,7,8 a sudden stop while running,7,8 or an evasive running maneuver in...