Perturbation Training Improves Knee Kinematics and Reduces Muscle Co-contraction After Complete Unilateral Anterior Cruciate Ligament Rupture

Abstract

Background and Purpose. Dynamic knee stabilization strategies of people who successfully compensate for the absence of an anterior cruciate ligament (ACL) ("copers") are different from those of people who do not compensate well for the injury ("noncopers"). Early after injury, certain patients ("potential copers") can increase the likelihood of successfully compensating for the injury by participating in 10 sessions of perturbation training. The purpose of this study was to determine how perturbation training alters muscle co-contraction and knee kinematics in potential copers. Subjects. Seventeen individuals with acute, unilateral ACL rupture who were categorized as potential copers and 17 subjects without injuries who were matched by age, sex, and activity level were recruited for this study. Methods. Motion analysis and electromyographic data were collected as subjects walked across a stationary or moving platform (horizontal translation) before and after perturbation training. Results. Before training, potential copers had higher co-contraction indexes and lower peak knee flexion angles than subjects without injuries. After training, potential copers' movement patterns more closely resembled those of subjects without injuries (ie, they showed reduced co-contraction indexes and increased peak knee flexion angles during stance). Discussion and Conclusion. Perturbation training reduced quadriceps femoris-hamstring muscle and quadriceps femoris-gastrocnemius muscle co-contractions and normalized knee kinematics in individuals with ACL rupture who were classified as potential copers. Findings from this study provide evidence for a mechanism by which perturbation training acts as an effective intervention for promoting coordinated muscle activity in a select population of people with ACL rupture. [Chmielewski TL, Hurd WJ, Rudolph KS, et al. Perturbation training improves knee kinematics and reduces muscle co-contraction after complete unilateral anterior cruciate ligament injuries. Phys Ther. 2005;85:740 -754.]

Gait Mechanics in Women of the ACL‐SPORTS Randomized Control Trial: Interlimb Symmetry Improves Over Time Regardless of Treatment Group

“…Participants in the SAPP + PERT treatment group did not receive the sham intervention but instead received the SAPP training described above plus 10 sessions of perturbation training (~30 min per session) . Perturbation training is a specific type of neuromuscular training designed to improve neuromuscular activation patterns and facilitate dynamic knee stability . During perturbation training, the patient stood on an unstable surface (i.e., rollerboard or rockerboard) while the physical therapist applied movements, or perturbations, to the surface.…”

“…Perturbation training is a specific type of neuromuscular training designed to improve neuromuscular activation patterns and facilitate dynamic knee stability . During perturbation training, the patient stood on an unstable surface (i.e., rollerboard or rockerboard) while the physical therapist applied movements, or perturbations, to the surface. Perturbations began in a blocked manner with small movements and were progressed by increasing the speed, magnitude, direction (e.g., adding diagonals or rotations), and manner in which the perturbations were delivered (e.g., blocked progressing to random; verbal cues progressing to no verbal cues).…”

“…Perturbations began in a blocked manner with small movements and were progressed by increasing the speed, magnitude, direction (e.g., adding diagonals or rotations), and manner in which the perturbations were delivered (e.g., blocked progressing to random; verbal cues progressing to no verbal cues). Sport‐specific distractions, such as throwing, catching, or passing a ball, were added during the later sessions . While the interventions, principles, and general progression were standardized, physical therapists were allowed clinical judgment to determine the optimal rate of progression for each individual athlete and appropriate selection of sport‐specific distractions.…”

“…Specifically, this randomized control trial was designed to test the effect of strength, agility, plyometric, and secondary prevention (SAPP) training with and without perturbation training (SAPP + PERT), a specific type of neuromuscular training. The scientific premise for this study was based on evidence that rehabilitation programs incorporating both strength and neuromuscular (perturbation) training have improved movement patterns among individuals after ACL injury, and that the effect of post‐operative rehabilitation and neuromuscular training on movement patterns was unkown . We recently reported our findings from the men of the ACL‐SPORTS trial (as recruitment occurred more quickly among the men) .…”

Effect of anatomic realignment on muscle function during gait in patients with medial compartment knee osteoarthritis

“…Statistical significance was set at P less than 0.05 except for muscle co‐contraction indices. An alpha level of P less than 0.1 was established in an effort to avoid a type I error given the highly variable nature of EMG data (25).…”