Toe Flexor Muscle Strength in Vocational Ballet Dancers: Reliability, Variability, and Minimal Detectable Change of a...

Area of Science:

• Biomechanics
• Sports Science
• Physiotherapy

Background:

• Toe flexor strength is vital for locomotion, balance, and athletic performance, particularly in activities like running, jumping, and dancing.
• Accurate assessment of foot muscle strength is challenging but crucial for training and rehabilitation.
• Strengthening the feet has gained attention in athletic and general populations.

Purpose of the Study:

• To investigate the within- and between-session reliability of toe flexor maximal voluntary isometric contraction (MVIC) using a custom-made dynamometer.
• To establish the measurement properties of a novel device for assessing foot muscle strength.

Main Methods:

• Twenty-five vocational ballet students (16.48 ± 1.2 years) participated in two sessions 48-72 hours apart.
• Toe flexor maximal voluntary isometric contraction (MVIC) was measured using a custom dynamometer with toes at 25° dorsiflexion.
• Three trials were conducted per session for each foot.

Main Results:

• Excellent between-session reliability was found for absolute MVIC (aMVIC) (ICC = 0.89-0.95) and normalized toe flexor strength (rTFS) (ICC = 0.91-0.95).
• Within-session reliability was also excellent (ICC = 0.92-0.95) for all measures.
• Minimal detectable change (MDC) ranged from 9.7% to 13.7%.

Conclusions:

• The custom toe flexor dynamometer demonstrates high reliability for measuring toe flexor strength.
• A familiarization session and three trials per session are recommended to minimize measurement variability.
• This tool has potential for research, rehabilitation monitoring, and assessing readiness in dancers.