CHANGES IN KNEE JOINT ANGLE DURING 1-HOUR OF WALKING AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

H. Shinohara¹, T. Haba¹, H. Ryota², Y. Umezaki¹, D. Kawamura¹, R. Sugawara¹

¹Graduate School of Aomori University of Health and Welfare, Physical Therapy, Aomori, Japan, ²Medical Corporation Ishikawa Hospital, Rehabilitation, Himeji, Japan

Background: Recently, the interest in anterior cruciate ligament (ACL) insufficiency has increased as multiple studies have shown that ACL injury, with or without ACL reconstruction, is a significant risk factor for knee osteoarthritis (OA). Therefore, prevention of OA is considered necessary in patients who have undergone ACL reconstruction. We speculate that a change in gait may be one mechanism predisposing such patients to OA. Numerous studies have analyzed gait after ACL reconstruction. However, most analyzed data from only a few steps; patients who have undergone ACL reconstruction often perform prolonged walking during activities of daily living. We therefore felt it was necessary to examine the kinematic changes that occur when walking for longer periods of time.

Purpose: The purpose of this study was to examine the change in kinematics of individuals who have undergone ACL reconstruction over time by analyzing knee joint angles during a one-hour walk.

Methods: We enrolled 16 female and 2 male participants of whom 8 women and 1 man had undergone ACL reconstruction. All individuals who had undergone ACL reconstruction were recruited more than 2 years postoperatively. The reflective marker three-dimensional (3D) position-time coordinates were sampled at 100Hz using a 3D camera system (Optitrack, Natural Point). The participants walked for one hour on a treadmill at a speed of 4.5km/h. One-minute measurements were taken every 10 minutes for a total of seven measurements. Visual3D (C-Motion, Inc.) was used to analyze the knee joint angles during the 25% stance phase and 50% stance phase.

Results: Two-way analysis of variance was performed to assess two factors: presence or absence of ACL reconstruction and measurement time. The results showed no main effect or interaction in the 25% stance phase, but a main effect of ACL reconstruction in the 50% stance phase (ACL group: 11.5±3.0°, Control group: 8.7±8.5° p=.028). There was no significant difference in the main effect or interaction of measurement time.

Conclusions: Researchers have postulated that individuals who undergo ACL reconstruction develop a characteristic gait style called quadriceps avoidance gait. Furthermore, the severity of knee OA is related to the weakness of quadriceps muscles in patients with OA. From this, we hypothesized that an effect on knee flexion movement during walking would emerge in those who have undergone ACL reconstruction. The results of this study showed that there was no change over time walking in either ACL reconstruction or healthy participants, but the increase in knee joint flexion angle at the 50% stance phase, which was observed from the beginning of walking in ACL reconstruction participants, was confirmed to remain over one hour of walking.

Implications: The findings suggest that knee angle during walking may be used as a strategy to prevent knee osteoarthritis in people who undergo ACL reconstruction.Physical therapists should consider mid stance knee joint angle in gait after ACL reconstruction.

Funding acknowledgements: None

Keywords:
ACL reconstruction
gait analysis
long walk

Topics:
Musculoskeletal: lower limb
Sport & sports injuries
Musculoskeletal

Did this work require ethics approval? Yes

Institution: Aomori University of Health and Welfare

Committee: Ethics Committee

Ethics number: 21055