Leg Strength, Preferred Walking Speed, and Daily Step Activity in Adults With Incomplete Spinal Cord Injuries

Abstract

Background:The reduction in physical activity that accompanies spinal cord injury (SCI) contributes to the development of secondary health concerns. Research has explored potential strategies to enhance the recovery of walking and lessen the impact of physical disability following SCI, but further work is needed to identify determinants of community walking activity in this population. Objectives: To quantify relationships among lower extremity strength (LES), preferred walking speed (PWS), and daily step activity (DSA) in adults with incomplete SCI (iSCI) and determine the extent to which LES and PWS predict DSA in persons with iSCI. Methods: Participants were 21 adults (age range, 21 to 62 years; AIS levels C and D) with iSCI. Maximal values of hip abduction, flexion, and extension, knee flexion and extension, and ankle dorsiflexion and plantar flexion were measured using handheld dynamometry and were summed to determine LES. PWS was calculated using a photoelectric cellbased timing system, and participants were fitted with activity monitors to measure DSA in a natural setting. Results: Statistically significant (P < .05) correlations of moderate to high magnitude (.74 to .87) were observed among LES, PWS, and DSA. Multiple regression analysis revealed that LES and PWS accounted for 83% (adjusted R

Supraspinal Control Predicts Locomotor Function and Forecasts Responsiveness to Training after Spinal Cord Injury

“…These functions are subserved by supraspinal reticular, vestibular, and cerebellar inputs. 43 As was first described in the 1970s, 44 the strong relationship between volitional control of the lower extremity muscles and walking ability [44][45][46][47][48][49][50][51][52][53][54][55][56] attests to the importance of supraspinal contributions to human walking. During human walking, neuronal activity related to lower extremity movement is represented in the primary motor and sensory cortices.…”

“…Another study found that the summed values of maximal force production (obtained with hand-held dynamometry) in the hip flexors, extensors, and abductors, knee flexors and extensors, and ankle dorsiflexors and plantar flexors was moderately correlated with walking speed, and strongly correlated with daily step activity. 56 Imaging and electrophysiological measures associated with walking capacity In recent years, there has been growing interest in identifying electrophysiological and radiographical biomarkers that can predict locomotor outcomes. 60,144,145 Recent evidence from studies of TMS 146 and EMG coherence 60,144 have provided additional support for the importance of corticospinal pathways in human walking.…”

The Ability to Walk After a Spinal Cord Injury with Emphasis on Exoskeletons: A Review

“…The 10 MWT has been shown to be a valid clinical measure of walking capability and to reliably reflect walking performance in real-life settings [19]. Walking speed on the 10 MWT in SCI patients correlates well with ambulation categories based on ambulatory milestones, as defined by van Hedel et al [25], (Table 1).…”

“…Literature suggests that a walking speed of 1.20 to 1.31 m/s is required for independent community ambulation [18]. However, several studies show an average walking speed of patients with SCI around 0.36 m/s [19][20][21]. Together with factors such as the ability to transfer and manage curbs, stairs and crowded areas, this could lead to a reduced independence in walking in the community.…”

“…Although these compensatory strategies enable patients with SCI to become more functionally mobile, paradoxically they contribute to a reduction in walking behavior [24]. According to Stevens et al [19], therapeutic interventions designed to increase community ambulation in patients with SCI should focus on strengthening the legs through resistance training, engaging in locomotor training or regularly participating in other forms of weight-supported physical activity involving the legs.…”