Effect of Concurrent Visual Feedback Frequency on Postural Control Learning in Adolescents

Effect of Reduced Feedback Frequencies on Motor Learning in a Postural Control Task in Young Adults

The effects of the use of reduced feedback frequencies on motor learning remain controversial in the scientific literature. At present, there is still controversy about the guidance hypothesis, with some works supporting it and others contradicting it. To shed light on this topic, an experiment was conducted with four groups, each with different feedback frequencies (0%, 33%, 67%, and 100%), which were evaluated three times (pre-test, post-test, and retention) during a postural control task. In addition, we tested whether there was a transfer in performance to another similar task involving postural control. As a result, only the 67% feedback group showed an improvement in their task performance in the post-test and retention evaluations. Nevertheless, neither group showed differences in motor transfer performance compared to another postural control task. In conclusion, the findings of this paper corroborate the hypothesis of guidance and suggest that the use of a reduced frequency of 67% is a better option for improving motor learning than options that offer feedback at a lower frequency, at all trials or not at all.

A Pilot Study Comparing the Effects of Concurrent and Terminal Visual Feedback on Standing Balance in Older Adults

While balance training with concurrent feedback has been shown to improve real-time balance in older adults, terminal feedback may simplify implementation outside of clinical settings. Similarly, visual feedback is particularly well-suited for use outside the clinic as it is relatively easily understood and accessible via ubiquitous mobile devices (e.g., smartphones) with little additional peripheral equipment. However, differences in the effects of concurrent and terminal visual feedback are not yet well understood. We therefore performed a pilot study that directly compared the immediate effects of concurrent and terminal visual feedback as a first and necessary step in the future design of visual feedback technologies for balance training outside of clinical settings. Nineteen healthy older adults participated in a single balance training session during which they performed 38 trials of a single balance exercise including trials with concurrent, terminal or no visual feedback. Analysis of trunk angular position and velocity features recorded via an inertial measurement unit indicated that sway angles decreased with training regardless of feedback type, but sway velocity increased with concurrent feedback and decreased with terminal feedback. After removing feedback, training with either feedback type yielded decreased mean velocity, but only terminal feedback yielded decreased sway angles. Consequently, this study suggests that, for older adults, terminal visual feedback may be a viable alternative to concurrent visual feedback for short duration single-task balance training. Terminal feedback provided using ubiquitous devices should be further explored for balance training outside of clinical settings.

Effectiveness of the Type of Feedback on Learning to Pass in Volleyball

Objective: To determine which type of feedback (visual, verbal, or both combined) facilitates to a greater extent the learning of a specific skill (passing in volleyball). Methods: Three groups of students between 14 and 15 years of age belonging to the third year of Compulsory Secondary Education in a Spanish public high school (n = 58) were randomly assigned a type of feedback implemented in the part of the syllabus dedicated to volleyball. The students’ knowledge, motor performance, accuracy, and self-perception about the action were evaluated before and after the intervention and enjoyment afterwards. Results: All the groups obtained improvements in all the variables studied (p < .05); the verbal and visual feedback group was the one that obtained greater improvements, showing also a greater enjoyment than the visual feedback group. Conclusions: It has been found that the use of the combination of verbal and visual feedback is most recommended for learning a specific skill, such as passing in volleyball.

Impact of Visual Biofeedback of Trunk Sway Smoothness on Motor Learning during Unipedal Stance

The assessment of trunk sway smoothness using an accelerometer sensor embedded in a smartphone could be a biomarker for tracking motor learning. This study aimed to determine the reliability of trunk sway smoothness and the effect of visual biofeedback of sway smoothness on motor learning in healthy people during unipedal stance training using an iPhone 5 measurement system. In the first experiment, trunk sway smoothness in the reliability group (n = 11) was assessed on two days, separated by one week. In the second, the biofeedback group (n = 12) and no-biofeedback group (n = 12) were compared during 7 days of unipedal stance test training and one more day of retention (without biofeedback). The intraclass correlation coefficient score 0.98 (0.93–0.99) showed that this method has excellent test–retest reliability. Based on the power law of practice, the biofeedback group showed greater improvement during training days (p = 0.003). Two-way mixed analysis of variance indicates a significant difference between groups (p < 0.001) and between days (p < 0.001), as well as significant interaction (p < 0.001). Post hoc analysis shows better performance in the biofeedback group from training days 2 and 7, as well as on the retention day (p < 0.001). Motor learning objectification through visual biofeedback of trunk sway smoothness enhances postural control learning and is useful and reliable for assessing motor learning.

Self-assessment during Jump Shot Drills Translates to Decreased Vertical Ground Reaction Forces during Single Limb Drop Jump Landing

Background

Prevention programs reduce hard and stiff landings associated with risk of anterior cruciate ligament (ACL) injury, yet cost and time are barriers to implementation. Providing feedback about landing mechanics during shooting drills at practices using minimal resources and time may improve adherence to educating athletes how to avoid risky mechanics associated with ACL injury when landing. Implementing video, auditory, written, and pictorial feedback into basketball practices to cue athletes on landing mechanics after taking a jump shot may soften the landing.

Purpose

The purpose of this study was to test whether implementing video, auditory, written, and pictorial feedback into a basketball practice jump shot drill (i.e., double limb drop jump landing task) will result in lesser vertical ground reaction force (vGRF) during a single limb drop jump landing without decreasing maximal jump height.

Study Design

Observational, Case-control Study.

Methods

During a summer league, 16 female high school basketball players were assigned to an intervention (Int) or control (Con) group. The Int group (n=8) utilized delayed video feedback and task cards (written and pictorial cues) at six practices while the Con group (n=8) received typical coaching only. Cost and compliance with the intervention were measured. Pre- and post-season data collections included five single limb drop jumps from a 31 cm high box onto force plates. The vGRF impulses over the first 10% of landing were calculated for each limb. Data did not differ between limbs, thus data for both limbs were pooled. Two mixed model ANOVAs were used to compare groups over time (p<0.05) for vGRF and maximum jump height, respectively.

Results

Compliance with the intervention was 100% and did not increase the time of drills. The implementation cost was less than $10. A time*group interaction (p=0.04; Int significantly decreased vGRF over time), main effect of time (p=0.004), and no main effect of group (p=0.412) were found for vGRF during single limb drop jump landings. A time*group interaction (p=0.03; Int significantly decreased max jump height over time), no main effect of time (p=0.10) and no main effect of group (p=0.32) were found for max jump height.

Conclusion

Athletes landed more softly and jumped less high during a single limb drop jump landing task after receiving feedback during jump shot drills. High team compliance may occur since the intervention required minimal resources and addressed different learning styles.

Level of Evidence

Level 3b.