Unplanned gait termination in individuals with multiple sclerosis

Cortical activity and spatiotemporal parameters during gait termination and walking: A preliminary study

Gait termination requires an interaction between the biomechanical and neuromuscular systems to arrest forward momentum. Currently, the biomechanical characteristics of gait termination have been demonstrated; however, the neural mechanism of gait termination remains unclear. This study aimed to investigate cortical activity during gait termination using functional near-infrared spectroscopy (fNIRS). Thirteen healthy younger adults (mean age:24.0 ± 1.7) participated in this study. All participants performed three experimental sessions: planned gait termination (PGT), unplanned gait termination (UGT), and walking. Each experimental session comprised a block paradigm design (three cycles; 20 s resting, 45 s task). Cortical activity in the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and primary motor cortex (M1) and spatiotemporal parameters were measured. We compared the cortical activities and spatiotemporal parameters among PGT, UGT, and walking sessions. In addition, we performed Pearson correlations between hemodynamic responses and spatiotemporal parameters. The PGT was activated in the right DLPFC, whereas the UGT and walking were activated in the left SMA (p < 0.05). Comparing cortical activation between sessions, both the PGT and UGT showed significantly higher activation in the right DLPFC than during walking (p < 0.05). There were no significant differences in cortical activity between PGT and UGT (p > 0.05). In addition, the gait termination time revealed moderate positive correlation with hemodynamic responses in the right DLPFC (p < 0.05). Our results indicate that the right DLPFC is associated with gait termination, regardless of gait termination type. Our findings provide the potential implication that the hemodynamic response in the right DLPFC would be a biomarker to evaluate the ability of gait termination.

Biomechanical Analysis of Unplanned Gait Termination According to a Stop-Signal Task Performance: A Preliminary Study

There is a correlation between cognitive inhibition and compensatory balance response; however, the correlation between response inhibition and gait termination is not clear.

OBJECTIVES

The purpose of this study was to investigate the gait parameters of the lower extremity that occurred during unplanned gait termination (UGT) in two groups classified by the stop-signal reaction time (SSRT).

METHODS

Twenty young adults performed a stop-signal task and an unplanned gait termination separately. UGT required subjects to stop on hearing an auditory cue during randomly selected trials. The spatiotemporal and kinematic gait parameters were compared between the groups during UGT.

RESULTS

In phase one, the fast group had a significantly greater angle and angular velocity of knee flexion and ankle plantar flexion than the slow group (p < 0.05). Phase two showed that the fast group had a significantly greater angle and angular velocity of knee extension than the slow group (p < 0.05). Concerning the correlation analysis, the angle and angular velocity of knee flexion and ankle plantar flexion showed a negative correlation with the SSRT during UGT in phase one (p < 0.05). Phase two showed that the angle and angular velocity of knee extension was negatively correlated with the SSRT during UGT (p < 0.05).

CONCLUSION

The shorter the SSRT, the greater the angle and joint angular velocity of the ankle or knee joint that were prepared and adjusted for gait termination. The correlation between the SSRT and UGT suggests that a participant's capacity to inhibit an incipient finger response is associated with their ability to make a corrective gait pattern in a choice-demanding environment.

A Proposal for Complex Gait Evaluation Using Dual-Task Gait Termination Time

CONTEXT

Gait termination time (GTT) has been used to predict falls in older adults but has not been explored in the sport rehabilitation setting. The incorporation of a concurrent cognitive task as a complex measure of gait in this clinical population could lead to better health-related outcomes.

OBJECTIVE

To compare the effect of planned and unplanned gait termination with and without a concurrent cognitive task on reaction time (RT), gait velocity, and GTT.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

Twenty young adults (females 60.0%, age 20.1 [0.9] y, height 169.5 [8.8] cm, mass 67.4 [10.8] kg).

INTERVENTION

Participants completed 6 planned and 6 unplanned gait termination trials on an instrumented gait mat with and without a cognitive task.

MAIN OUTCOME MEASURES

The authors measured RT (s), gait velocity (m/s), GTT (s), and normalized GTT (s2/m). A 2 (motor) × 2 (cognitive) repeated-measures analysis of variance (α = .05) was used; significant interaction effects were explored using Bonferroni-corrected t tests (α < .008).

RESULTS

Participants walked more slowly during dual-task trials compared with single-task trials (F1,19 = 4.401, P = .050). Participants walked significantly more slowly with a cognitive task during planned (P < .001, mean difference = -0.184 m/s, 95% CI, -0.256 to -0.111) and unplanned (P = .001, mean difference = -0.111 m/s, 95% CI, -0.173 to -0.050) gait termination. Participants walked significantly more slowly (P < .001, mean difference = -0.142 m/s, 95% CI, -0.210 to -0.075) when performing the most difficult task, unplanned termination with a cognitive task, than when performing the least difficult task, planned termination with no cognitive task. We observed a cognitive task main effect such that adding a cognitive task increased RT (F1,19 = 16.375, P = .001, mean difference = -0.118 s, 95% CI, -0.178 to -0.057) and slowed normalized GTT (F1,19 = 5.655, P = .028, mean difference = -0.167 s2/m, 95% CI, -0.314 to -0.020).

CONCLUSIONS

Overall, participants displayed more conservative gait strategies and slower RT, normalized GTT, and gait velocity as task difficulty increased. More investigation is needed to truly understand the clinical meaningfulness of these measures in athletic injuries.

The effect of yoga practice on muscular strength improvement in patients with multiple sclerosis

Background/Aims

Multiple sclerosis is a common condition in the central nervous system where patients experience many issues, including muscle weakness. This study offers an investigation of continuous hatha yoga exercises on patients with multiple sclerosis.

Methods

A total of 22 participants with multiple sclerosis were selected, 11 were allocated to the intervention group, and 11 to the control group. In both groups, surface electromyography and dynamometer were performed at the beginning and the end of the study. The intervention group undertook 90-minute sessions of hatha yoga training three times a week for 6 months and the control group did not do any particular exercise during this period.

Results

Dynamometer results indicated that yoga significantly improved the muscle strength of the participants with multiple sclerosis (before the intervention: 40.00 Nm ± 14.66 Nm vs 56.82 Nm ± 20.28 Nm after the intervention, P=0.037). However, there was no significant difference in muscle strength changes between the intervention and control groups (16.82 Nm ± 23.26 Nm vs -2.86 Nm ± 23.36 Nm, P=0.171). Yoga significantly increased participants muscle strength according to the surface electromyography signals (before the intervention: 39.91 V ± 8.86 V vs 54.09 v ± 8.95 V after the intervention, P=0.007). The muscle strength of the control group participants with multiple sclerosis decreased after 6 months, however it was not statistically significant (41.55 Nm ± 9.3 Nm vs 34.55 Nm ± 8.36 Nm, P=0.073). The comparison of changes showed that the surface electromyography signals in the intervention group were significantly higher than those of the control group (P=0.001).

Conclusions:

Yoga exercises, in addition to common multiple sclerosis treatment methods, can be considered as a complementary therapy to improve the physical aspects of multiple sclerosis symptoms.