Falls after spinal cord injury: a systematic review and meta-analysis of incidence proportion and contributing factors.

INTRODUCTION: Falls are detrimental to the well-being of individuals with spinal cord injury (SCI). To establish effective fall prevention initiatives, a comprehensive understanding of falls after SCI is needed. OBJECTIVES: To report the incidence proportion of falls and summarize the factors contributing to falls in individuals with SCI. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Eight databases were searched. Abstracts/full articles were screened by two researchers independently. Data concerning study design, participant characteristics, and the incidence proportion, factors, and consequences of falls were extracted. Risk of bias was assessed using a domain-based approach that considered sampling and measurement bias. The incidence proportions of falls were pooled for ambulators and wheelchair users separately using random-effects meta-analyses, and compared descriptively for inpatients and community-dwelling individuals. Fall-related factors were organized according to the Biological, Behavioral, Social & Economic and Environmental Model of fall risk. RESULTS: The search resulted in 1706 articles; 24 unique studies were included. The risk of sampling bias was high. All but one study focused on community-dwelling individuals; 78% (95% confidence interval 73-83%, I2 = 0%) of ambulators and 69% (95% confidence interval 60-76%, I2 = 59%) of wheelchair users fell ≥1 over 12 months. In contrast, only 13% of inpatients fell. Most fall-related factors were categorized as biological (e.g., muscle weakness), behavioral (e.g., inattentiveness) or environmental (e.g., uneven surfaces). CONCLUSIONS: Falls are frequent among community-dwelling individuals with SCI. A variety of biological, behavioral, and environmental factors contribute to falls, some of which are modifiable and may be addressed through SCI-specific fall prevention initiatives.

A single session of exercise as a modulator of short-term learning in healthy individuals.

BACKGROUND: A single session of aerobic exercise is linked to faster motor responses; however, the effect on rate of short-term learning is less clear. The objective was to evaluate the influence of a single bout of aerobic exercise on the rate of short-term acquisition of a shape-letter association task requiring a motor response. METHODS: 23 [11 females, age 20.8±2.7years] healthy young adults were evaluated using a randomly assigned crossover design which was counterbalanced for order before and after moderate (exercise) and light (control) intensity cycle ergometry. Participants performed 3 blocks, with each block consisting of one round of training and testing. During training, participants were tasked with learning 6 unique shape-letter associations. Subsequent testing required a key press response to a visually presented shape pattern. Response time and error rates were used to assess acquisition over the 3 blocks of testing. RESULTS: Mean response time was faster post-exercise relative to the other testing periods, and approached statistical significance compared to post-control (p<0.07). However, no significant difference in response time reduction (difference between test block 1 and test block 3) was identified between the four evaluations (pre and post the exercise and control conditions). Error rate reduction (test block 1 minus test block 3) revealed that individuals had the smallest change in error rate post-exercise (p<0.05). Follow-up analyses revealed fewer errors in test block 1 and test block 2 post-exercise which approached statistical significance (p=0.06) suggesting near-perfect error rates were obtained after only 2 testing blocks post-exercise compared to 3 blocks in the other testing periods. CONCLUSIONS: Support for augmentation of short-term learning was mixed as errors were reduced post-exercise while response time was not different between evaluations. Future work should include neurophysiological evaluation and a retention test to better elucidate the influence of aerobic exercise on rate of short-term learning.