The Myotonometer: Not a Valid Measurement Tool for Active Hamstring Musculotendinous Stiffness

Area of Science:

• Biomechanics
• Musculoskeletal Research
• Sports Medicine

Background:

• Hamstring musculotendinous stiffness (MTS) is a key factor in lower-extremity injury risk.
• Current laboratory methods for MTS assessment lack clinical validity.
• A need exists for a reliable and valid clinical tool to measure hamstring MTS for injury prevention and rehabilitation monitoring.

Purpose of the Study:

• To evaluate the validity and reliability of the Myotonometer for assessing active hamstring MTS.
• To compare Myotonometer measurements with the established damped oscillatory technique.

Main Methods:

• A descriptive laboratory study involving 33 healthy participants.
• Hamstring MTS was measured using both the Myotonometer and the damped oscillatory technique.
• Intraclass correlations assessed intrasession, intersession, and interrater reliability.
• Pearson correlation coefficients determined criterion validity.

Main Results:

• The Myotonometer exhibited good intrasession (ICC = .807) and interrater (ICC = .830) reliability.
• Moderate intersession reliability (ICC = .693) was observed.
• The Myotonometer did not show valid measurement of hamstring MTS compared to the damped oscillatory technique (r = .346, P = .061).

Conclusions:

• The Myotonometer is not a valid instrument for measuring active hamstring MTS.
• Despite lacking validity for MTS, the Myotonometer shows potential for clinical use in assessing tissue compliance, muscle tone, or spasticity.
• Further research is required to develop portable, clinically valid tools for measuring active hamstring MTS to aid in injury prevention and rehabilitation.