Linking Gait Biomechanics and Daily Steps After ACL Reconstruction

Abstract

Purpose: Aberrant biomechanics and altered loading frequency are associated with poor knee joint health in osteoarthritis development. After anterior cruciate ligament reconstruction (ACLR), individuals demonstrate underloading (lesser vertical ground reaction force (vGRF)) with stiffened knee gait biomechanics (lesser knee extension moment (KEM) and knee flexion angle) and take fewer daily steps as early as 6 months after surgery. The purpose of this cross-sectional laboratory study is to compare gait biomechanics throughout stance between individuals 6-12 months after ACLR who take the lowest, moderate, and highest daily steps. Methods: Individuals with primary, unilateral history of ACLR between the ages of 16 and 35 yr were included (n = 36, 47% females; age, 21 ± 5 yr; months since ACLR, 8 ± 2). Barefoot gait biomechanics of vGRF (body weight), KEM (body weight  height), and knee flexion angle during stance were collected and time normalized. Average daily steps were collected via a waist-mounted accelerometer in free-living settings over 7 d. Participants were separated into tertiles based on lowest daily steps (3326-6042 daily steps), moderate (6043-8198 daily steps), and highest (8199-12,680 daily steps). Biomechanical outcomes of the ACLR limb during stance were compared between daily step groups using functional waveform gait analyses. Results: There were no significant differences in sex, body mass index, age, or gait speed between daily step groups. Individuals with the lowest daily steps walk with lesser vGRF and lesser KEM during weight acceptance, and lesser knee flexion angle throughout stance in the ACLR limb compared with individuals with highest and moderate daily steps. Conclusions: After ACLR, individuals who take the fewest daily steps also walk with lesser vGRF during weight acceptance and a stiffened knee strategy throughout stance. These results highlight complex interactions between joint loading parameters after ACLR.

Return to sports after ACL injury 5 years from now: 10 things we must do

“…It is apparent that current rehabilitation programs do not yet effectively target strength deficits [ 119 ], postural stability [ 69 ] and aberrant movement patterns after ACLR [ 47 , 64 , 102 ]. Quadriceps weakness and aberrant movement patterns are suggested to be risk factors for an early onset of osteoarthritis and second ACL injury risk [ 74 , 88 ].…”

Joint and Limb Loading during Gait in Adults with ACL Reconstruction: Comparison between Single-Step and Cumulative Load Metrics

“…Lastly, the biomechanical changes observed in our study may not translate to walking overground or in free-living conditions where walking speed is rarely constant. Recently, a host of works have aimed to evaluate free-living activity habits after ACLR and have generally shown reduced daily steps and lesser physical activity engagement compared with healthy populations (52)(53)(54). With recent advancements in IMU technology (i.e., pressure sensors, accelerometers), combining daily step/ physical activity monitoring with IMU may permit gait assessments in a real-world environment and aid in further understanding loading habits during everyday activity after ACLR (52,54).…”

Monitoring External Workload With Wearable Technology After Anterior Cruciate Ligament Reconstruction: A Scoping Review

“…15,24,25,34 Two studies conducted assessments in the later stages of rehabilitation (6-12 months postoperatively). 29,32 One study conducted assessments throughout rehabilitation's early and later stages. 49 Thirteen studies conducted assessments a minimum of 1 year after surgery.…”

“…Nineteen studies assessed the external workload of typical daily activities in an uncontrolled free-living environment. These assessment periods were either 1 day, 24,25 2 days, 15 7 days, 7,8,10,18,19,[28][29][30][32][33][34]51 13 days, 20,21 2 periods of 28 days, 31 or 231 days. 49 Workloads were also assessed during training activities such as rehabilitation, workouts, and practice 49 and competition, including elite-level rugby matches.…”

“…32 Participants with low daily step counts walked with lesser vertical ground-reaction force during weight acceptance (d ¼ 1.29; 95% CI, 0.96-1.62), a stiffened knee strategy, lesser knee extension moment (d ¼ 0.80; 95% CI, 0.48-1.11), and knee flexion angle (d ¼ 1.03; 95% CI, 0.70-1.35) throughout stance compared with those with high daily step counts. 32 Ezzat et al 20 found no significant differences in MVPA between patients with ACLR (1.1 years postoperatively, approximately 13 months) and healthy controls; however, patients with ACLR had fewer mean minutes per day of vigorous PA compared with the controls (mean difference, -1.22; 95% CI, -2.40 to -0.04]). In a follow-up study, Ezzat et al 21 19 found no significant differences in daily steps or MVPA between the patients with ACLR (51.9 ± 37.0 months postoperatively) and healthy controls.…”