The role of tendon stiffness in development of equine locomotion with age
Article first published online: 8 NOV 2010
© 2010 EVJ Ltd
Equine Veterinary Journal
Special Issue: Proceedings of the 8th International Conference on Equine Exercise Physiology
Volume 42, Issue Supplement s38, pages 556–560, November 2010
How to Cite
ADDIS, P. R. and LAWSON, S. E. M. (2010), The role of tendon stiffness in development of equine locomotion with age. Equine Veterinary Journal, 42: 556–560. doi: 10.1111/j.2042-3306.2010.00296.x
- Issue published online: 8 NOV 2010
- Article first published online: 8 NOV 2010
- [Paper received for publication 25.06.10; Accepted 30.06.10]
- tendon stiffness
Reasons for performing study: The flexor tendons support the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints during stance phase and since tendon stiffness and strain changes with age, it is likely that kinematics are also age-dependent.
Hypothesis: Maximum MCP and DIP angles decrease in the young horse, plateau in the mature horse and increase towards senescence.
Methods: The distal limbs of 57 walking horses age 3–212 months were filmed and digitised with an automated tracking system. Maximum MCP and DIP angles during stance phase were used to calculate strain in the superficial and deep digital flexor tendons. Horses were divided into 3 age groups; young (3–35 months), mature (36–99 months) and older horses (100–212 months). Pearson's correlation coefficients were calculated to determine the relationship between age and kinematics.
Results: Tendon strain decreased in young horses, stayed constant in mature horses and increased in older horses. Joint angles showed significant negative correlation in young horses, with coefficients of −0.88 (MCP) and −0.81 (DIP). In mature horses, correlations were not significant (P = 0.2 for MCP; P = 0.5 for DIP). In older horses, angles showed significant positive correlation, with coefficients of 0.62 (MCP) and 0.48 (DIP).
Conclusions: Joint angles decreased in the young horse as tendon stiffness increases, remained constant in the mature horse where tendon stiffness is constant and increased in older horses as tendons weakens and stiffness decreases. Strain patterns were similar to those found in vitro.
Potential relevance: Changing tendon stiffness appeared to influence the development and degeneration of gait. This has implications for studying musculoskeletal development, especially for identification of normal and pathological development.