Out of Lab Longitudinal Gait Assessment of Participants Pre and Post Anterior Cruciate Ligament Reconstruction Surgery: An Observational Longitudinal Study.

Objective: To evaluate the longitudinal changes in knee sagittal kinematics pre- and post-anterior cruciate ligament reconstruction (ACLR) during varying walking speeds in non-laboratory environments. A secondary objective describing the hip and ankle joint kinematics.

Design: Longitudinal observational study.

Setting: Hospital.

Patients or other participants: Forty ACLR patients and 17 healthy matched controls were recruited.

Main outcome measure(s): Knee joint sagittal kinematics measured using seven inertial measurement units at pre-surgery, three-, and five-months post-surgery while walking at slow, normal, and fast speeds.

Results: At pre-surgery, compared to the contralateral limb, the injured knee exhibited greater minimum flexion during normal and fast walking (p≤.008) and exhibited less knee flexion at the first peak (p=.006). SPM revealed significant differences throughout the gait cycle at all speeds (p≤.033). Compared to controls, the injured knee had greater minimum flexion during normal and slow walking (p≤.025). At three months, compared to the contralateral limb, the injured knee showed increased minimum flexion across all speeds (p≤.005) and exhibited less knee flexion at the first peak during fast walking (p<.001). SPM indicated significant differences throughout the gait cycle at all speeds (p≤.028). Compared to controls, the injured knee remained more flexed at the minimum angle across all speeds (p<.001) and exhibited less knee flexion at the first peak during slow walking (p=.031). At five months, differences between limbs were reduced, with significant differences in minimum flexion at all speeds (p≤.027). SPM differences were limited to specific gait cycle portions during normal and fast walking (p≤.011). Compared to controls, the injured knee remained more flexed at the minimum angle during slow and normal walking (p≤.005). Lastly, hip adaptations resolved while ankle asymmetries persisted during terminal stance.

Conclusions: ACLR patients demonstrated progressive improvements in knee sagittal kinematics, indicating a recovery trend. However, the recovery was non-linear across different walking speeds.