Age at spinal cord injury determines muscle strength

Improving translatability of spinal cord injury research by including age as a demographic variable

Pre-clinical and clinical spinal cord injury (SCI) studies differ in study design, particularly in the demographic characteristics of the chosen population. In clinical study design, criteria such as such as motor scores, neurological level, and severity of injury are often key determinants for participant inclusion. Further, demographic variables in clinical trials often include individuals from a wide age range and typically include both sexes, albeit historically most cases of SCI occur in males. In contrast, pre-clinical SCI models predominately utilize young adult rodents and typically use only females. While it is often not feasible to power SCI clinical trials to test multi-variable designs such as contrasting different ages, recent pre-clinical findings in SCI animal models have emphasized the importance of considering age as a biological variable prior to human experiments. Emerging pre-clinical data have identified case examples of treatments that diverge in efficacy across different demographic variables and have elucidated several age-dependent effects in SCI. The extent to which these differing or diverging treatment responses manifest clinically can not only complicate statistical findings and trial interpretations but also may be predictive of worse outcomes in select clinical populations. This review highlights recent literature including age as a biological variable in pre-clinical studies and articulates the results with respect to implications for clinical trials. Based on emerging unpredictable treatment outcomes in older rodents, we argue for the importance of including age as a biological variable in pre-clinical animal models prior to clinical testing. We believe that careful analyses of how age interacts with SCI treatments and pathophysiology will help guide clinical trial design and may improve both the safety and outcomes of such important efforts.

Adaptive sports for promoting physical activity in community-dwelling adults with stroke: A feasibility study

BACKGROUND

Despite proven health benefits of regular participation in physical activities (PA), adults with stroke fail to achieve recommended levels of PA. Sports being an enjoyable activity is more likely to encourage participation. Therefore, the objectives of the present study are i) to develop and test the feasibility of adaptive sports for promoting PA and Quality of Life (QoL) in community-dwelling adults with stroke, and ii) to explore the participants perception and experiences of playing adaptive sports.

METHODS

Two focus groups were conducted among the eight experts and a person with stroke to develop adaptive sports. To test the feasibility of these adaptive sports, in a multi methods study eighteen community dwelling adults with stroke were recruited. Participants played adaptive sports twice a week for two months in a community center. Participants pre and post intervention PA levels and QoL were measured. Participants were also interviewed at the end of the program to explore their experiences of participation in adaptive sports.

RESULTS

At the end of the program retention rate of the participants was 83.33% and there was a significant improvement in PA levels, while the improvement in QoL was not statistically significant. Participants expressed positive experience with the program. There were no adverse events during or after the participation. Health benefits, fitness, and fun were reported as facilitators, while lack of access to the sporting facility and lack of caregiver support were reported as barriers to participation.

CONCLUSION

Adaptive sports appear to be safe, feasible, and well accepted by the adults with stroke.

Outcomes following an adaptive rock climbing program in a person with an incomplete spinal cord injury: A case report

Purpose: The purpose of this case report was to document outcomes following a rock climbing program for an individual with an incomplete spinal cord injury (SCI). Case Description: The participant was a 61 year-old male who sustained a C6 cervical AIS D SCI. Initially, he was only able to climb 30% of the rock wall with assistance and was unable to climb unassisted. Intervention: Outcome measures included muscle strength, arm girth, the Mini-Balance Evaluation Systems Test (Mini-BESTest), distance climbed, climbing performance, and the Quality of Life Profile for Adults with Physical Disabilities. The intervention included two 90-min sessions per week for 19 weeks. One session comprised traditional physical therapy and the second took place at an indoor rock climbing gym. Outcomes: Following the intervention, he was able to climb 100% of the wall with assistance and 48% unassisted. He made improvements in all categories of the quality of life scale, while changes in muscle strength and arm girth varied. No improvements were noted in balance. Conclusions: A task-based physical therapy program focusing on strengthening and rock climbing-specific activities improved the rock climbing ability of an individual with an incomplete cervical SCI.

Low-Force Muscle Activity Regulates Energy Expenditure after Spinal Cord Injury

Reduced physical activity is a primary risk factor for increased morbidity and mortality. People with spinal cord injury (SCI) have reduced activity for a lifetime, as they cannot volitionally activate affected skeletal muscles. We explored whether low-force and low-frequency stimulation is a viable strategy to enhance systemic energy expenditure in people with SCI.

PURPOSE

This study aimed to determine the effects of low stimulation frequency (1 and 3 Hz) and stimulation intensity (50 and 100 mA) on energy expenditure in people with SCI. We also examined the relationship between body mass index and visceral adipose tissue on energy expenditure during low-frequency stimulation.

METHODS

Ten individuals with complete SCI underwent oxygen consumption monitoring during electrical activation of the quadriceps and hamstrings at 1 and 3 Hz and at 50 and 100 mA. We calculated the difference in energy expenditure between stimulation and rest and estimated the number of days that would be necessary to burn 1 lb of body fat (3500 kcal) for each stimulation protocol (1 vs 3 Hz).

RESULTS

Both training frequencies induced a significant increase in oxygen consumption above a resting baseline level (P < 0.05). Energy expenditure positively correlated with stimulus intensity (muscle recruitment) and negatively correlated with adiposity (reflecting the insulating properties of adipose tissue). We estimated that 1 lb of body fat could be burned more quickly with 1 Hz training (58 d) as compared with 3 Hz training (87 d) if an identical number of pulses were delivered.

CONCLUSION

Low-frequency stimulation increased energy expenditure per pulse and may be a feasible option to subsidize physical activity to improve metabolic status after SCI.