Differences in pre-swing posture between successful and tripping steps in individuals with stroke

Area of Science:

• Neurology
• Biomechanics
• Rehabilitation Science

Background:

• Tripping is a primary cause of falls in individuals post-stroke.
• Mechanisms of intrinsic tripping-related near-falls during walking, especially in pre-swing, are not well understood.
• Existing research often focuses on external perturbations or lower limb kinematics.

Purpose of the Study:

• To investigate if altered thoracic and pelvic posture during the pre-swing phase contribute to tripping-related near-falls in individuals with stroke.
• To determine if this contribution is independent of lower limb joint kinematics.

Main Methods:

• Retrospective analysis of three-dimensional motion data from walking assessments.
• Included 39 individuals with stroke who experienced tripping-related near-falls.
• Compared kinematic and spatiotemporal parameters during pre-swing between successful gait and near-fall trials, analyzing thorax/pelvis alignment, pelvic position, step parameters, and lower limb joint kinematics.

Main Results:

• Near-fall trials exhibited greater anterior pelvic tilt and thoracic tilt compared to successful trials.
• Increased anterior pelvic displacement was observed in near-fall trials.
• Reduced non-paretic step length and greater non-paretic hip flexion were associated with near-falls.

Conclusions:

• Tripping-related near-falls in stroke survivors are linked to impaired thoracic and pelvic control during the pre-swing phase.
• These findings suggest proximal postural control deficits are more critical than isolated paretic knee/ankle motion issues.
• Interventions should consider proximal postural control and non-paretic stance limb function for fall prevention.