Feasibility of a hand-held myotonometry device for measuring biomechanical muscle parameters in horses.

Overview

• This study assessed the feasibility of using a hand-held myotonometry device (MyotonPRO) to measure specific biomechanical properties of the longissimus dorsi muscle in healthy horses.
• The research focused on muscle frequency, stiffness, and decrement, examining measurements on both sides of the horse to evaluate symmetry and relationships with age and body condition.

Introduction

• The longissimus dorsi muscle is a key muscle along the horse’s back involved in posture and movement.
• Measuring biomechanical parameters like muscle tone (frequency), stiffness, and decrement (related to muscle elasticity and damping) can provide objective data on muscle status.
• Existing assessments of equine muscle condition are often subjective; thus, a reliable and portable measurement device could improve diagnosis, injury prevention, and monitoring recovery.
• The MyotonPRO is a hand-held device designed for non-invasive muscle assessment, previously used in humans but less evaluated in equine applications.

Methods

• The study involved 50 adult healthy horses with no reported musculoskeletal issues.
• Measurements were performed on the longissimus dorsi muscle in the thoracolumbar region on both the left and right sides while horses stood squarely to ensure standardized posture.
• The MyotonPRO device was set to triple-scan mode, capturing reliable readings of muscle frequency (Hz), stiffness (N/m), and decrement (unitless index related to muscle elasticity/damping).
• Data analysis included comparing results between left and right sides to evaluate symmetry.
• Correlation analysis was carried out to see if age or body score influenced the biomechanical parameters on at least one side (left side specifically reported).

Results

• Muscle Frequency:
  • Left side mean = 21.66 ± 2.88 Hz
  • Right side mean = 21.45 ± 2.75 Hz
  • No significant difference between sides indicating consistent muscle tone.
• Muscle Stiffness:
  • Left side mean = 535.94 ± 82.87 N/m
  • Right side mean = 525.41 ± 75.15 N/m
  • Symmetrical measurements without statistical difference.
• Decrement (related to muscle elasticity and viscoelastic properties):
  • Left side mean = 1.68 ± 0.34
  • Right side mean = 1.71 ± 0.26
  • Again, no significant asymmetry found.
• Correlations:
  • On the left side, some biomechanical parameters correlated with age and body condition score, suggesting these factors influence muscle properties.
  • The exact strength and parameters of correlation were not specified, but this points to potential biological relevance of the measurements.

Discussion

• The data supports that the MyotonPRO device can reliably capture biomechanical muscle parameters in horses.
• The lack of significant side-to-side differences supports muscle symmetry in healthy horses, which is expected in normal musculoskeletal function.
• Correlation with age and body score implies the device may detect physiologically relevant changes in muscle over time or with body condition.
• A portable, easy-to-use hand-held device like MyotonPRO offers an objective alternative to subjective manual palpation or clinical evaluation.
• This can enhance clinical assessments by helping monitor muscle health, identify injury risks early, and follow recovery processes more quantitatively.

Conclusion

• The study confirms the feasibility and usefulness of the MyotonPRO device for measuring muscle biomechanical parameters in horses in a field setting.
• Such technology holds promise for improving equine musculoskeletal care by introducing objective, repeatable muscle assessments.