Context: Joint loading following anterior cruciate ligament reconstruction (ACL-R) is thought to influence long-term outcomes. However, our understanding of the role of meniscus repair at the time of ACL-R on early joint loading is limited. Objective: To assess if differences in total energy absorption and energy absorption contribution of the hip, knee, and ankle exist in the early stages of rehabilitation between patients who received an isolated ACL-R and those with concomitant meniscal repairs. Design: Cross-sectional. Setting: Clinical laboratory. Patients: Fifty-nine human subjects, including 27 who underwent ACL-R and 32 who underwent ACL-R with concomitant meniscal repairs. Main Outcome Measure: The total energy absorption and the energy absorption contribution of each joint of both the involved and uninvolved limbs during a double-limb squat task. Results: There were significant differences in energy absorption contribution between groups at the knee joint (P = .01) and the hip joint (P = .04), but not at the ankle joint (P = .48) of the involved limb. Post hoc analysis indicates that preoperative hip and knee loading differences exist and when you control for preoperative loading (analysis of covariance), the postsurgery difference was not significant. Conclusions: The results of the study suggest that the additional surgical procedure of MR may not have had negative effects on joint loading during squatting at 12 weeks.
Joseph Hannon, J. Craig Garrison, Sharon Wang-Price, Shiho Goto, Angellyn Grondin, James Bothwell and Curtis Bush
Jason D. Stone, Adam C. King, Shiho Goto, John D. Mata, Joseph Hannon, James C. Garrison, James Bothwell, Andrew R. Jagim, Margaret T. Jones and Jonathan M. Oliver
Purpose: To provide a joint-level analysis of traditional (TS) and cluster (CS) set structure during the back-squat exercise. Methods: Eight men (24  y, 177.3 [7.9] cm, 82.7 [11.0] kg, 11.9 [3.5] % body fat, and 150.3 [23.0] kg 1-repetition maximum [1RM]) performed the back-squat exercise (80%1RM) using TS (4 × 6, 2-min interset rest) and CS (4 × [2 × 3], 30-s intraset rest, 90-s interset rest), randomly. Lower-limb kinematics were collected by motion capture, as well as kinetic data by bilateral force platforms. Results: CS attenuated the loss in mean power (TS −21.6% [3.9%]; CS −12.4% [7.5%]; P = .042), although no differences in gross movement pattern (sagittal-plane joint angles) within and between conditions were observed (P ≥ .05). However, joint power produced at the hip increased from repetition (REP) 1 through REP 6 during TS, while a decrease was noted at the knee. A similar pattern was observed in the CS condition but was limited to the hip. Joint power produced at the hip increased from REP 1 through REP 3 but returned to REP 1 values before a similar increase through REP 6, resulting in differences between conditions (REP 4, P = .018; REP 5, P = .022). Conclusions: Sagittal-plane joint angles did not change in either condition, although CS elicited greater power. Differing joint power contributions (hip and knee) suggest potential central mechanism that may contribute to enhanced power output during CS and warrant further study. Practitioners should consider incorporating CS into training to promote greater power adaptations and to mitigate fatigue.