Study Design: Controlled single-group pretest/posttest design. Objective: The purpose of this study was to determine if a 6-week neuromuscular training program designed to decrease the incidence of anterior cruciate ligament (ACL) injuries would improve single-limb postural stability in young female athletes. We hypothesized neuromuscular training would result in an improvement in postural stability, with the greatest improvement taking place in the medial-lateral direction. Background: Balance training has become a common component of programs designed to prevent ACL injury. Rehabilitation programs can improve postural stability following ACL injury and reconstruction; however, there is limited information available which quantifies improvement of postural stability following neuromuscular training designed to prevent ACL injuries in a healthy population. Methods and Measures: Forty-one healthy female high school athletes (mean age, 15.3 years; age range, 13-17 years) participated in this study. Single-limb postural stability for both lower extremities was assessed with a Biodex Stability System. The neuromuscular training program consisted of three 90-minute training sessions per week for 6 weeks. Following the completion of the training program, each subject was re-evaluated to determine change in total, anterior-posterior, and medial-lateral single-limb stability. Two-way analysis of variance models were used to determine differences between pretraining and posttraining and between limbs. Results: The subjects showed a significant improvement in single-limb total stability (P = .004) and anterior-posterior stability (P = .001), but not medial-lateral stability (P = .650) for both the right and left lower extremity following training. In addition, the subjects demonstrated significantly better total postural stability on the right side as compared to the left (P = .026). Conclusions: A 6-week neuromuscular training program designed to decrease the incidence of ACL injuries improves objective measures of total and anterior-posterior single-limb postural stability in high school female athletes.

J Orthop Sports Phys Ther. 2004;34(6):305-316. doi:10.2519/jospt.2004.1325

Key Words: anterior cruciate ligament, balance, knee, prevention, proprioception

Traditionally, open kinetic chain rehabilitation and evaluation have been used as the primary tool to assess a patient's strength and readiness to progress to a higher functional level. More recently, closed kinetic chain activities have been developed and well documented as an alternate means to prepare and evaluate a patient's ability to return to a higher functional level. However, a dearth in recent literature comparing the correlation between an open kinetic chain isokinetic strength test and performance on a functional performance test exists. Therefore, the purpose of this study was to examine the relationship between a knee extensor strength and functional performance test, specifically the 1-legged hop for distance. Twenty subjects (x¯ = 20.7 years), with no prior history of lower extremity injury, participated in the study consisting of isokinetic evaluation of the quadriceps muscle using a Kinetic Communicator and a 1-legged hop for distance. Isokinetic testing was performed at 240°/sec. All tests were performed on the dominant and nondominant limbs. Pearson product moment correlation coefficients for peak torque and distance hopped were .78 for the dominant leg and .65 for the nondominant leg (p < .05). These results support the belief that isokinetic strength does not correlate strongly with functional tasks.

J Orthop Sports Phys Ther. 1995;22(5):202-206.

Key Words: functional testing, muscle strength, knee

Rehabilitation following anterior cruciate ligament (ACL) reconstruction has undergone a relatively rapid and global evolution over the past 25 years. However, there is an absence of standardized, objective criteria to accurately assess an athlete’s ability to progress through the end stages of rehabilitation and safe return to sport. Return-to-sport rehabilitation, progressed by quantitatively measured functional goals, may improve the athlete’s integration back into sport participation. The purpose of this clinical commentary is to introduce an example of a criteria-driven algorithm for progression through return-to-sport rehabilitation following ACL reconstruction. Our criteria-based protocol incorporates a dynamic assessment of baseline limb strength, patient-reported outcomes, functional knee stability, bilateral limb symmetry with functional tasks, postural control, power, endurance, agility, and technique with sport-specific tasks. Although this algorithm has limitations, it serves as a foundation to expand future evidence-based evaluation and to foster critical investigation into the development of objective measures to accurately determine readiness to safely return to sport following injury.

J Orthop Sports Phys Ther. 2006; 36(6):385-402. doi:10.2519/jospt.2006.2222

Key Words: anterior cruciate ligament, knee rehabilitation, lower extremity, sport injury