Gait modification strategies in trunk over right stance phase in patients with right anterior cruciate ligament deficiency

- Gait modification strategies of trunk were apparent in patients with right ACL-D.
- When walking, trunk anterior rotation over the right stance phase was higher.
- When ascending stairs, trunk lateral flexion to the left was higher over the right stance.
- When descending stairs, trunk lateral flexion to the left was higher over the right stance.
- When descending stairs, either trunk posterior lean or lateral flexion to right was higher.

This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency (ACL-D). Thirty-six patients with right chronic ACL-D were recruited, as well as 36 controls. A 3D optical video motion capture system was used during gait and stair ambulation. Kinematic variables of the trunk and kinematic and kinetic variables of the knee were calculated. Patients with chronic right ACL-D exhibited many significant abnormalities compared with controls. Trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns (P < 0.05). Compared with controls, trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended (P < 0.01). Trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment (P = 0.01), when descending stairs at the maximal knee coronal plane moment (P < 0.01), and when descending stairs at the end of the knee coronal plane moment (P = 0.03). Trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment (P < 0.01) and when the knee transverse plane moment ended (P < 0.01); during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns (all P < 0.01). In conclusion, gait modification strategies of the trunk were apparent in patients with ACL-D. These results provide new insights about diagnosis and rehabilitation of chronic ACL-D (better use of walking and stair tasks as part of a rehabilitation program).