Takeuchi, K, Takemura, M, Nakamura, M, Tsukuda, F, and Miyakawa, S. Effects of active and passive warm-ups on range of motion, strength, and muscle passive properties in ankle plantarflexor muscles. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to examine the effects of active and passive warm-ups on flexibility and strength of calf muscles. Fourteen healthy males (age: 23.1 ± 2.6 years, height: 172.7 ± 5.6 cm, and body mass: 64.5 ± 7.0 kg) performed 3 types of warm-ups respectively for 10 minutes in a random order: an active warm-up by pedaling a cycling ergometer, an active warm-up doing repeated isometric contractions, and a passive warm-up in a hot water bath. To assess flexibility, range of motion (ROM) of ankle dorsiflexion, passive torque of ankle plantarflexion, and muscle tendon junction (MTJ) displacement were measured and then muscle tendon unit (MTU) stiffness was calculated. After the flexibility assessment, peak torque during maximum voluntary isometric contraction was measured to assess the isometric strength. These data were compared before and after each warm-up. As a result, all 3 types of warm-ups increased ROM (p < 0.05) and passive torque at terminal ROM (p < 0.01), but there were no significant changes in MTU stiffness or MTJ displacement. The active warm-up by pedaling a cycling ergometer increased peak torque during isometric contraction (p < 0.05), whereas the other warm-ups did not show significant alterations. In conclusion, the active warm-up with aerobic exercise increased flexibility and strength of the calf muscles.

The purpose of the present study was to investigate the effects of using a combination of static stretching and aerobic exercise on muscle tendon unit stiffness and muscle strength in the ankle plantar-flexor muscles. Fifteen healthy males (23.3 ± 2.7 years, 170.3 ± 6.5 cm, 64.9 ± 8.7 kg) received three different interventions, in random order. Intervention 1 received 10 min of aerobic exercise after five cycles of one minute of static stretching. Intervention 2 received 10 min of aerobic exercise before the static stretching. Intervention 3 received 5 min of aerobic exercise both before and after the static stretching. The range of motion of ankle dorsiflexion, stretch tolerance, muscle tendon unit stiffness, peak torque of ankle plantarflexion, and the amplitude of electromyography were measured. In all interventions, the range of motion and stretch tolerance significantly increased (p < 0.05), but muscle tendon unit stiffness decreased significantly for all interventions (p < 0.05). Peak torque of ankle plantar flexion and amplitude of electromyography significantly increased for Interventions 1 and 3 (p < 0.05), while these significantly decreased for Intervention 2 (p < 0.05). These data indicated that range of motion and stretch tolerance were increased, but muscle tendon unit stiffness was decreased regardless of the order of static stretching and aerobic exercise. Aerobic exercise after static stretching increased the peak torque and amplitude of electromyography.

The purpose of the present study was to investigate static stretching and dynamic stretching protocol. 138 coaches of 21 diŠerent sports completed a self-reporting questionnaire. The questionnaire was split into four sections and containedˆxed-response questions. Section One identiˆed participant demographics. The second and third sections required the participants to detail the static and dynamic stretching they used. The fourth section of the questionnaire identiˆed how participants learned about stretching. There were 126 coaches using static or dynamic stretching, while 12 coaches did not. Thirtynine coaches used only static stretching, 10 coaches used only dynamic stretching, and 77 coaches used both types of stretching. The purposes of static stretching were to increase ‰exibility and to prevent injuries. The purposes of dynamic stretching were improvement of performance and prevention of injuries. The duration of one bout of static and dynamic stretching in a warm-up were 21.8±13.2 and 22.1±16.2 seconds, respectively. A common way to learn about stretching was participation in training sessions. Coaches should use SS for a greater length of time to achieve their purposes. The results of the present study showed gaps between evidence and practice.

ObjectivesThe purpose of the present study was to compare the effects of static stretching (SS) on the range of motion and vertical jump height between the quadriceps, hamstrings and triceps surae in collegiate basketball players.MethodsFourteen male collegiate basketball players (20.2±0.7 years, 179.0±5.0 cm, 71.9±8.3 kg) underwent 5 min of SS for the quadriceps, hamstrings and triceps surae, in random order. Before and after each stretch, the range of motion (ROM) and vertical jump height were measured.ResultsROM of the quadriceps, hamstrings and triceps surae were increased without any difference of relative change in the range. The vertical jump height showed no change after SS of the quadriceps and hamstrings, while it decreased after SS of the triceps surae (p<0.05).ConclusionThese results suggested that SS for the triceps surae may have a large impact on jump performance.

No abstract