Investigating proactive balance control in individuals with incomplete spinal cord injury while walking on a known slippery surface

Control of center of mass motion during walking correlates with gait and balance in people with incomplete spinal cord injury

Background

There is evidence that ambulatory people with incomplete spinal cord injury (iSCI) have an impaired ability to control lateral motion of their whole-body center of mass (COM) during walking. This impairment is believed to contribute to functional deficits in gait and balance, however that relationship is unclear. Thus, this cross-sectional study examines the relationship between the ability to control lateral COM motion during walking and functional measures of gait and balance in people with iSCI.

Methods

We assessed the ability to control lateral COM motion during walking and conducted clinical gait and balance outcome measures on 20 ambulatory adults with chronic iSCI (C1-T10 injury, American Spinal Injury Association Impairment Scale C or D). To assess their ability to control lateral COM motion, participants performed three treadmill walking trials. During each trial, real-time lateral COM position and a target lane were projected on the treadmill. Participants were instructed to keep their lateral COM position within the lane. If successful, an automated control algorithm progressively reduced the lane width, making the task more challenging. If unsuccessful, the lane width increased. The adaptive lane width was designed to challenge each participant's maximum capacity to control lateral COM motion during walking. To quantify control of lateral COM motion, we calculated lateral COM excursion during each gait cycle and then identified the minimum lateral COM excursion occurring during five consecutive gait cycles. Our clinical outcome measures were Berg Balance Scale (BBS), Timed Up and Go test (TUG), 10-Meter Walk Test (10MWT) and Functional Gait Assessment (FGA). We used a Spearman correlation analysis (ρ) to examine the relationship between minimum lateral COM excursion and clinical measures.

Results

Minimum lateral COM excursion had significant moderate correlations with BBS (ρ = -0.54, p = 0.014), TUG (ρ = 0.59, p = 0.007), FGA (ρ = -0.59, p = 0.007), 10MWT-preferred (ρ = -0.59, p = 0.006) and 10MWT-fast (ρ = -0.68, p = 0.001).

Conclusion

Control of lateral COM motion during walking is associated with a wide range of clinical gait and balance measures in people with iSCI. This finding suggests the ability to control lateral COM motion during walking could be a contributing factor to gait and balance in people with iSCI.

Modified stepping behaviour during outdoor winter walking increases resistance to forward losses of stability

Healthy humans are proficient at maintaining stability when faced with diverse walking conditions, however, the control strategies that lead to this proficiency are unclear. Previous laboratory-based research has predominantly concluded that corrective stepping is the main strategy, but whether this finding holds when facing everyday obstacles outside of the laboratory is uncertain. We investigated changes in gait stability behaviour when walking outdoors in the summer and winter, hypothesizing that as ground conditions worsened in the winter, the stepping strategy would be hindered. Stability would then be maintained through compensatory strategies such as with ankle torques and trunk rotation. Data was collected in the summer and winter using inertial measurement units to collect kinematics and instrumented insoles to collect vertical ground reaction forces. Using the goodness of fit for a multivariate regression between the centre of mass state and foot placement we found that, counter to our hypothesis, stepping was not hindered by winter conditions. Instead, the stepping strategy was modified to increase the anterior-posterior margin of stability, increasing the resistance to a forward loss of stability. With stepping being unhindered, we did not observe any additional compensation from the ankle or trunk strategies.

Effect of torso training on unstable surface on lower limb motor function in patients with incomplete spinal cord injury

OBJECTIVES

To investigate the effect of torso training on unstable surface on lower limb motor function in patients with incomplete spinal cord injury.

METHODS

A total of 80 patients with incomplete spinal cord injury caused by thoracolumbar fracture admitted in Ningbo Yinzhou No.2 Hospital from April 2020 to December 2021 were randomly divided into control group and study group, with 40 cases in each group. In addition to routine training, the control group received torso training on stable surface and the study group received torso training on unstable surface. The gait, lower limb muscle strength, balance function, lower limb function, mobility and nerve function of the two groups were compared.

RESULTS

After treatment, the stride length, stride frequency and comfortable walking speed improved in the two groups (all P<0.05), and the improvements in study group were more significant (all P<0.05). The muscle strength of quadriceps femoris, gluteus maximus, hamstring, anterior tibialis and gastrocnemius were improved in the two groups (all P<0.05), and the improvements in study group were more significant (all P<0.05); the total trajectories of static eye opening and static eye closing gravity center movement in the two groups were significantly shorter (all P<0.05), and the improvements in the study group were more significant (all P<0.05). The dynamic stability limit range and the American Spinal Injury Association (ASIA) lower extremity motor score, Berg balance scale, modified Barthel index scale in the two groups were significantly higher (all P<0.05), and these scores in study group were significantly higher than those in the control group (all P<0.05). Both groups showed a significant improvement in ASIA grade (all P<0.05), and the improvement in the study group was significantly better (P<0.05).

CONCLUSIONS

Torso training on unstable surface can effectively improve the gait and lower limb muscle strength of patients with incomplete spinal cord injury and improve the lower limb motor function.

The experiences of people with incomplete spinal cord injury or disease during intensive balance training and the impact of the program: A qualitative study

STUDY DESIGN

Qualitative descriptive study.

OBJECTIVES

To gain insight into if and how participation in intensive balance training impacted the daily lives and risk of falling of people living with incomplete spinal cord injury or disease (SCI/D), as well as to understand what motivated participation and what benefits and challenges, if any, they experienced while completing training.

SETTING

Tertiary rehabilitation hospital.

METHODS

Semi-structured interviews were conducted three to four months after 20 participants with incomplete SCI/D completed either Perturbation-based Balance Training or Conventional Intensive Balance Training as part of a randomized clinical trial. Interviews were transcribed verbatim and coded using conventional content analysis by two researchers. Codes were discussed for consensus, and subcategories and categories were created, which were confirmed by another two researchers.

RESULTS

The following categories were identified: 1) goals of balance training, 2) valuable components of balance training, 3) physical gains from balance training, 4) psychosocial gains from participating in balance training, and 5) unique aspects of Perturbation-based Balance Training. Each category consisted of several subcategories.

CONCLUSIONS

Collecting qualitative data facilitated the evaluation of the meaningfulness of the balance training programs to the participants. These findings demonstrate that balance training was perceived as beneficial and enjoyable for individuals with incomplete SCI/D, and that these programs provided challenge and educational opportunities for the participants while improving balance confidence and reducing perceived fall risk. These findings have implications to direct future research studies or implementation of balance training in rehabilitation.