Strength and Step Activity After Eccentric Resistance Training in Those With Incomplete Spinal Cord Injuries

Eccentric resistance training with neurological conditions: A meta analysis

BACKGROUND

People with neurological conditions are exposed to muscle wasting resulting in reduced strength and endurance. Both deficiencies negatively impact gait and balance, each of which can be benefited by strengthening exercises. Unfortunately, people with neurological conditions often do not have the ability to perform traditional weight training as their endurance and strength fail to meet the minimum threshold for improvement. An alternative to traditional, full range of motion lifting is eccentric resistance training (ERT).

RESEARCH QUESTION

The current systematic review and meta-analysis sought to evaluate the efficacy of ERT against conventional therapeutic modalities or weightlifting on walking speed, Timed Up and Go (TUG), and maximum voluntary isometric contraction (MVIC) in individuals with neurological conditions.

METHODS

Web of Science, PubMed, and Academic Search Complete were searched until September 1, 2020, followed by a manual search on December 3, 2021. Publications were included if they were peer reviewed, available in English, consisted of a pre-specified neurological disorder, involved human subjects, had an eccentric and "traditional" therapy; and reported at least one of the outcome measures at both pre- and post-intervention.

RESULTS

Thirteen studies of human subjects (n = 297) and 47 standardized mean differences (SMD) were included in the multilevel model analysis. The analysis revealed a small, albeit non-significant effect on performance (TUG, MVIC, walking speed) when comparing traditional therapies and ERT (SMD: 0.136; 96; 95 % CI: -0.0002, 0.050).

SIGNIFICANCE

There appears to be no difference between ERT and traditional therapy or weightlifting on measured outcomes. In this way, ERT is as effective as traditional therapeutics and full range of motion weightlifting to improve movement in clinical populations. Practitioners working with populations with neurological conditions may consider supplementing or replacing traditional strengthening activities with ERT as clients can complete greater volumes of work with lower metabolic demand.

Corticospinal-motor neuronal plasticity promotes exercise-mediated recovery in humans with spinal cord injury

Rehabilitative exercise in humans with spinal cord injury aims to engage residual neural networks to improve functional recovery. We hypothesized that exercise combined with non-invasive stimulation targeting spinal synapses further promotes functional recovery. Twenty-five individuals with chronic incomplete cervical, thoracic, and lumbar spinal cord injury were randomly assigned to 10 sessions of exercise combined with paired corticospinal-motor neuronal stimulation (PCMS) or sham-PCMS. In an additional experiment, we tested the effect of PCMS without exercise in 13 individuals with spinal cord injury with similar characteristics. During PCMS, 180 pairs of stimuli were timed to have corticospinal volleys evoked by transcranial magnetic stimulation over the primary motor cortex arrive at corticospinal-motor neuronal synapses of upper- or lower-limb muscles (depending on the injury level), 1-2 ms before antidromic potentials were elicited in motor neurons by electrical stimulation of a peripheral nerve. Participants exercised for 45 min after all protocols. We found that the time to complete subcomponents of the Graded and Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) and the 10-m walk test decreased on average by 20% after all protocols. However, the amplitude of corticospinal responses elicited by transcranial magnetic stimulation and the magnitude of maximal voluntary contractions in targeted muscles increased on overage by 40-50% after PCMS combined or not with exercise but not after sham-PCMS combined with exercise. Notably, behavioural and physiological effects were preserved 6 months after the intervention in the group receiving exercise with PCMS but not in the group receiving exercise combined with sham-PCMS, suggesting that the stimulation contributed to preserve exercise gains. Our findings indicate that targeted non-invasive stimulation of spinal synapses might represent an effective strategy to facilitate exercise-mediated recovery in humans with different degrees of paralysis and levels of spinal cord injury.

Exploring the causes and impacts of falls among ambulators with spinal cord injury using photovoice: a mixed-methods study

OBJECTIVES

This study explored: (1) fall circumstances experienced by ambulators with spinal cord injury (SCI) over a 6-month period, (2) the impacts of falls-related injuries and fall risk and (3) their preferences/recommendations for fall prevention.

DESIGN

A sequential explanatory mixed-methods design with two phases.

SETTING

A Canadian SCI rehabilitation hospital and community setting.

PARTICIPANTS

Thirty-three ambulators with SCI participated in phase 1 and eight participants that fell in phase 1 participated in phase 2.

METHODS

In phase 1, fall circumstances were tracked using a survey that was completed each time a participant fell during the 6-month tracking period. Phase 2 involved photovoice; participants took photographs of factors that influenced their fall risk and how their fall risk impacted their work/recreational activities. Participants discussed the photographs and topics related to fall prevention in an individual interview and a focus group.

RESULTS

Of the 33 participants, 21 fell in 6 months. Falls commonly occurred in the home while participants were changing positions or walking. Most falls occurred in the morning or afternoon. In phase 2, interviews and focus group discussion revealed three themes: (1) falls are caused by bodily impairments (eg, impaired reactive response during slips and trips and weakness and altered sensation in legs/feet), (2) impacts of fall-related injuries and fall risk (eg, psychosocial effects of fall-related injuries, limiting community participation due to the risk of falling and activity-dependent concern of falling) and (3) approaches to fall prevention (eg, fall prevention strategies used, components of fall prevention and utility of professional fall prevention strategies/interventions).

CONCLUSIONS

Fall prevention interventions/strategies should focus on minimising a person's fall risk within their home as most falls occurred in the home environment. Ambulators with SCI would benefit from education and awareness about common fall circumstances that they may encounter in their daily lives.