Background: Much of the existing research concerning the use of video feedback (VFB) to enhance motor learning has been undertaken under strictly controlled experimental conditions. Few studies have sought to explore the impact of VFB on the skill learning experience of the students in a structured, school-based physical education (PE) setting. Most of those studies have only used qualitative approaches to implicate the potential value of VFB to enhance skill acquisition, students' engagement or selfassessment ability. Using a quantitative approach, the aim of this study was to investigate effects of using VFB on motor skill acquisition, selfassessment ability and motivation in a school-based learning environment (structured PE programme) with novice children learning a gymnastic skill. Method: Two French classes of beginners took part in a typical five-week learning programme in gymnastics. During each of the five, weekly lessons participants carried out the same warm-up routine and exercises. The experimental group (10 girls-8 boys, 12.4 ± 0.5 years) received VFB intermittently when learning a front handstand to flat back landing. VFB was given after every five attempts, combined with self-assessment and verbal instructions from the teacher. The control group (12 girls-13 boys, 12.6 ± 0.4 years) received exactly the same training but was not given VFB. In order to assess progress in motor skills, the arm-trunk angle (handshoulder-hip) was measured in the sagittal plane just as the hips formed a vertical line with the shoulders. Motivation was assessed using the Situational Motivation Scale questionnaire (Guay, F., R. J. Vallerand, and C. Blanchard. 2000. "On the Assessment of Situational Intrinsic and Extrinsic Motivation: The Situational Motivation Scale (SIMS)." Motivation and Emotion 24 (3): 175-213), and self-assessment ability was measured by self-perception task scores. Results: Statistical analysis of arm-trunk angle values showed significant differences only for the VFB group between the fifth lesson and all other lessons. Between lessons 4 and 5, the arm-trunk angle value increased significantly from 146.6 ± 16.9 degrees to 161.2 ± 14.2 degrees (p < .001; ES = 0.94). Self-assessment scores improved significantly for the VFB group between lesson 1 and lesson 2 (p < 0.01, ES = 1.79) and between lesson 4 to lesson 5 (p < .01, ES = 0.94). Amotivation decreased significantly for the VFB group between lesson 1 and lesson 5 (3.06 ± 1.42 vs. 2.12 ± 0.62, p < .001, ES = −0.89).

This study examined in pubescent swimmers the effects on front crawl performances of a 6-week plyometric training (PT) in addition to the habitual swimming program. Swimmers were assigned to a control group (n = 11, age: 14.1 ± 0.2 years; G(CONT)) and a combined swimming and plyometric group (n = 12, age: 14.3 ± 0.2 years; GSP), both groups swimming 5.5 h · wk(-1) during a 6-week preseason training block. In the GSP, PT consisted of long, lateral high and depth jumps before swimming training 2 times per week. Pre and posttests were performed by jump tests (squat jump [SJ], countermovement jump [CMJ]) and swim tests: a gliding task, 400- and 50-m front crawl with a diving start (V400 and V50, m · s(-1)), and 2 tests with a water start without push-off on the wall (25 m in front crawl and 25 m only with kicks). Results showed improvement only for GSP for jump tests (Δ = 4.67 ± 3.49 cm; Δ = 3.24 ± 3.17 cm; for CMJ and SJ, respectively; p < 0.05) and front crawl tests (Δ = 0.04 ± 0.04 m · s(-1); Δ = 0.04 ± 0.05 m · s(-1); for V50 and V400, respectively; p < 0.05). Significant correlations were found for GSP between improvements in SJ and V50 (R = 0.73, p < 0.05). Results suggested a positive effect of PT on specific swimming tasks such as dive or turn but not in kicking propulsion. Because of the practical setup of the PT and the relevancy of successful starts and turns in swimming performances, it is strongly suggested to incorporate PT in pubescent swimmers' training and control it by jump performances.

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This study aims to determine whether the arm coordination observed at different stroke rates (SR, number of arm stroke cycles per minute) differs according to the level of expertise. Thirteen non-expert (G(NE)) and 14 expert (G(E)) swimmers swam crawl five 25-m lengths at five stroke rate values: 35, 40, 45, 50, and 55 cycles.min(-1). Results show that the pattern of 45 % of G(NE) switched from the catch-up (a lag time is performed between the propulsive phases of the two arms) to the superposition coordination mode (both arms pushing simultaneously during a short period of the cycle) between 45 and 50 cycles.min(-1). Patterns of 62.4 % of G(E) switched in the same way between 50 and 55 cycles.min(-1). Significant differences in coordination patterns were found between G(NE) and G(E) only when SR was set at 45 cycles.min(-1). As non-expert swimmers seldom produce the superposition mode, but adopt this pattern when required to swim at high stroke rate values, it is suggested that this coordination mode is an emergent property of the movement.