The amount of practice really matters: specificity of practice may be valid only after sufficient practice

The effect of stroboscopic vision on performance in a football specific assessment

Purpose: This study aimed to investigate how restricted visual feedback affects performance in a football-specific skills assessment that incorporates the coupling of football a-specific perceptual information with football-specific motor actions. Methods: The Footbonaut is a 14x14m cage equipped with 8 ball dispensers and 64 targets measuring passing accuracy and time to complete each pass. Eighty-four amateur male participants (19.5 ± 5.4 years old; 13.1 ± 6.0 years experience) completed two sessions under two different visual conditions: stroboscopic and normal vision. Results: A linear regression revealed that performance under normal conditions was significantly associated (p < 0.001) with the performance decrement under stroboscopic vision conditions. Players were then subdivided into skilled (S; top 25%) and less-skilled (LS; bottom 25%) groups. Restricting visual feedback impacted the average time required to complete the passes in both S and LS groups equally (S: +0.18 s; LS: + 0.12 s; p = 0.385), yet S athletes' accuracy (-11.1%) was more heavily reduced under restricted visual conditions compared to their Normal condition; whereas the LS athletes' accuracy remained relatively unchanged (-1.9%). Conclusion: Therefore, stroboscopic vision may be used to induce performance errors during practice to stimulate larger training effects, particularly in more skilled players.

Seeing Is Believing: Blind Putting Drills Confer No Advantage to the Novice Golfer

Purpose: Golf coaches may recommend "blind" putting drills in which golfers close their eyes to improve their feel. Research on specificity of learning suggests, however, that adding or removing a source of sensory information after practicing under differing circumstances can cause performance decrements. Specificity of learning is also dependent upon specific task requirements. The purpose of this study was to examine whether golf putting, requiring body positioning and aiming an implement, would benefit from blind training. Method: Novice golfers (n = 24) in Vision Training (VT) & No-Vision Training (NVT) groups completed 108 trials of a 10-ft putt. After a 24-hr delay, both groups completed sighted- and blind-putting tests. Results: Acquisition results revealed Group × Block interactions in RE (p = .025) and y-VE (p = .032). Post hoc procedures revealed significant differences between the groups on Block 2 (p = .017), with the NVT group producing longer mean RE. During testing, RE and x-VE results revealed Group × Test interactions (p = .027 & .041), such that performance of the VT group suffered when transferred to blind putting, while performance of the NVT group did not differ when transferred. Conclusion: NVT did not confer any advantage for subsequent performance with vision. Moreover, results were not consistent with the specificity of learning hypothesis and suggest that putting does not rely on complete sensory integration to support subsequent performance. Presumably, task requirements related to body positioning provided adequate sensory cues for successful performance.

Pain Induced during Both the Acquisition and Retention Phases of Locomotor Adaptation Does Not Interfere with Improvements in Motor Performance

Cutaneous pain experienced during locomotor training was previously reported to interfere with retention assessed in pain-free conditions. To determine whether this interference reflects consolidation deficits or a difficulty to transfer motor skills acquired in the presence of pain to a pain-free context, this study evaluated the effect of pain induced during both the acquisition and retention phases of locomotor learning. Healthy participants performed a locomotor adaptation task (robotized orthosis perturbing ankle movements during swing) on two consecutive days. Capsaicin cream was applied around participants' ankle on both days for the Pain group, while the Control group was always pain-free. Changes in movement errors caused by the perturbation were measured to assess global motor performance; temporal distribution of errors and electromyographic activity were used to characterize motor strategies. Pain did not interfere with global performance during the acquisition or the retention phases but was associated with a shift in movement error center of gravity to later in the swing phase, suggesting a reduction in anticipatory strategy. Therefore, previously reported retention deficits could be explained by contextual changes between acquisition and retention tests. This difficulty in transferring skills from one context to another could be due to pain-related changes in motor strategy.

The specificity of practice hypothesis in goal-directed movements: visual dominance or proprioception neglect?

The study aimed to examine whether modifying the proprioceptive feedback usually associated with a specific movement would decrease the dominance of visual feedback and/or decrease, which appears to be the neglect of proprioceptive feedback in ensuring the accuracy of goal-directed movements. We used a leg positioning recall task and measured the recall error after 15 and 165 acquisition trials performed with both vision and proprioception or proprioception only, under either a normal or a modified proprioception condition (i.e., with a 1-kg load attached to the participants' ankle). Participant learning was evaluated in transfer with proprioception only. In support of the specificity of practice hypothesis, the recall errors in acquisition were significantly smaller when practice occurred with both vision and proprioception, in either the loaded or the unloaded leg condition, and they increased significantly in transfer when vision was withdrawn. An important finding of the study highlighted that withdrawing vision after 165 acquisition trials had less deleterious effects on the recall errors when practice occurred under the loaded leg condition. Under that modified condition, recall errors in transfer were similar when practice occurred with and without vision, whereas larger errors were observed following practice with vision under the normal proprioceptive condition. Overall, these results highlighted the dominance of vision in ensuring accurate leg positioning recall and revealed that the dominance of vision is such that the processing of proprioceptive feedback may be neglected. Importantly, modifying the proprioceptive feedback has the advantage of reducing what appears to be the neglect of proprioceptive information when movement execution occurs in a visuo-proprioceptive context. Practical considerations for rehabilitation are discussed at the end of the manuscript.