The Effects of Two Foot Strengthening Interventions on Toe Flexor Strength and Jumping Performance in Vocational Ballet Dancers: A Randomized Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 49
- 试验地点
- 2
- 主要终点
- Maximal voluntary isometric contraction (MVIC) of the toe flexors muscles
研究概览
简要总结
Professional dancers subject their feet to high forces through frequent jumping, repeated heel rises, insufficient shoe cushioning, and a high degree of foot mobility. To prevent injuries and improve jumping performance, dancers are recommended to strengthen the muscles of the lower extremities.
The foot muscles, especially the toe flexors, play an important role as shock absorbers and motors for the foot by absorbing and generating mechanical energy, which is essential for human locomotion. Furthermore, they serve as a link between the powerful leg extensor muscles and the ground, transmitting the energy generated by the larger muscle groups. This makes them essential components of overall athletic performance. However, the impact of foot muscle strength on dancers´ jumping performance remains uncertain. Therefore, the aim of this study is to investigate the effectiveness of two training programs designed to strengthen the toe flexor muscles in dancers. For this project, a 6.5-week intervention with ballet students from a vocational ballet school is planned. Before and after the intervention, all study participants will perform tests to assess foot muscle strength and jumping performance.
详细描述
This study aims to develop two different toe flexor (TF) exercise programs for vocational dancers to enhance TF strength and jumping performance. It is hypothesized that i) both training programs increase TF strength and jumping performance, ii) horizontal jumps are more affected than vertical jumps, and iii) the TF exercise program with the TF strengthening device has a greater impact on TF strength.
Participants
Participants will be recruited from a vocational ballet school via an email detailing the study outline. They and their legal guardians (for participants under 18 years old) will be informed of the potential risks and benefits of the study. They will provide written informed consent prior to the measurements. Participants will then be assigned to either a control group, a toe flexor device experimental group, or a heel rise experimental group. The schedule includes three and a half weeks of training, a 12-day break due to the school schedule, followed by another three weeks of training. This will result in a total of 26 training sessions. An experienced trainer will supervise all training sessions. The control group will continue with the ballet school´s normal training schedule.
Data collection and management
An intervention protocol will be kept to collect information on compliance and progression of the training, such as the number of repetitions and the resistance applied. Data analysis will be performed according to the intention-to-treat (ITT) principle, in which participants are analyzed according to their original treatment group assignment. An additional researcher will manage reporting for adverse effects (such as delayed onset muscle soreness) and adverse events. All data collected in this study will be anonymized, personal identifiers removed, and data coded to protect the identities of the participants.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
盲法说明
After the participants have completed the pre-measurements, they will be assigned to their group allocation. The intervention´s nature precludes blinding the participants and the trainer; however, a supervisor will monitor data collection.
入排标准
- 年龄范围
- 14 Years 至 19 Years（Child, Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- •Any recent lower leg or foot injuries.
- •Chronic pain in the lower extremities.
结局指标
主要结局
Maximal voluntary isometric contraction (MVIC) of the toe flexors muscles
时间窗: Measurements will be performed one week prior to and one week after the intervention.
The post-intervention difference between the three groups in MVIC of the toe flexors measured with a custom-made toe flexor dynamometer in a seated position (90° angle in the hips and knees) where the foot is secured with a strap. Participants will push with their toes against a pedal and hold this isometric contraction for 2-3 seconds. The strength will be normalized by body weight (N/kg).
次要结局
- Vertical jump - Countermovement jump (CMJ) - Jump height (cm)(Measurements will be performed one week prior to and one week after the intervention.)
- Vertical jump - CMJ - changes in force parameters(Measurements will be performed one week prior to and one week after the intervention.)
- Vertical jump - Sauté jump - jump height (cm)(Measurement will be performed one week prior to and one week after the intervention.)
- Vertical jump - Sauté - changes in force parameters(Measurements will be performed one week prior to and one week after the intervention.)
- Horizontal jump - Long jump - jump distance (cm)(Measurements will be performed one week prior to and one week after the intervention.)