Trunk Control during Gait: Walking with Wide and Narrow Step Widths Present Distinct Challenges

Abstract

The active control of the trunk plays an important role in frontal plane gait stability. We characterized trunk control in response to different step widths using a novel feedback system and examined the different effects of wide and narrow step widths as they each present unique task demands. Twenty healthy young adults walked on a treadmill at 1.25 m/s at five prescribed step widths: 0.33, 1.67, 1, 1.33, 1.67 times preferred step width. Motion capture was used to record trunk kinematics, and surface electromyography was used to record longissimus muscle activation bilaterally. Vector coding was used to analyze coordination between pelvis and thorax segments of the trunk. Results showed that while center of mass only varied across step width in the mediolateral direction, trunk kinematics in all three planes were affected by changes in step width. Angular excursions of the trunk segments increased only with wider widths in the transverse plane. Thorax-pelvis kinematic coordination was affected more by wider widths in transverse plane and by narrower widths in the frontal plane. Peak longissimus activation and bilateral co-activation increased as step widths became narrower. As a control task, walking with varied step widths is not simply a continuum of adjustments from narrow to wide. Rather, narrowing step width and widening step width from the preferred width represent distinct control challenges that are managed in different ways. This study provides foundation for future investigations on the trunk during gait in different populations.

Young adults with recurrent low back pain demonstrate altered trunk coordination during gait independent of pain status and attentional demands

“…Armour Smith and colleagues reported no difference in trunk intersegmental coordination between asymptomatic persons with a history of recurrent LBP and controls during walking turns with and without divided attention [8]. Both studies mentioned above report axial plane coordination, while we chose to focus on frontal plane coordination mostly because of the sensitivity it demonstrates to the demands of the task to walk with a narrow step width [28]. Two previous studies by Rowley and colleagues reported frontal plane movement during a continuous balance-dexterity task.…”

“…Kinematic data were low-pass filtered at 10 Hz with a dual-pass 4 th order Butterworth filter. The frontal plane trunk kinematic coordination was chosen because of its sensitivity in response to narrow step width [28], and was calculated using vector coding analysis described by Needham et al [29]. An angle-angle diagram was first constructed, then coupling angle was determined as the angle of the vector between two adjacent data points in time relative to the right horizontal (Fig 1B).…”

Individuals with recurrent low back pain exhibit further altered trunk control in remission than when in pain

“…We performed test-retest comparisons and did not find evidence indicating previous exposure having an effect (Supplementary figure 4). Additionally, despite good to excellent test-re-test reliability in the control participants 32 , reliability in individuals with recurrent LBP should be examined as it may not be the same as the back-healthy controls.…”

“…Participants were instrumented with reflective markers placed on the lower extremity and trunk. 32 Kinematic data were recorded by an 11-camera Qualysis motion capture system (Qualisys Inc., Gothenburg, Sweden) at 125 Hz. Surface electromyography (EMG) was collected using bipolar silver chloride electrodes with an interelectrode distance of 22 mm.…”

Young adults with recurrent low back pain demonstrate altered trunk coordination during gait independent of pain status and attentional demands

“…Armour Smith and colleagues reported no difference in trunk inter-segmental coordination between asymptomatic persons with a history of recurrent LBP and controls during walking turns with and without divided attention [8]. Both studies mentioned above report axial plane coordination, while we chose to focus on frontal plane coordination mostly because of the sensitivity it demonstrates to the demands of the task to walk with a narrow step width [28]. Two previous studies by Rowley and colleagues reported frontal plane movement during a continuous balance-dexterity task.…”