Effects of exercise on biomechanical properties of the superficial digital flexor tendon in foals.
OBJECTIVE
To determine the effects of exercise on biomechanical properties of the superficial digital flexor tendon (SDFT) in foals.


METHODS
43 Dutch Warmblood foals.


METHODS
From 1 week until 5 months of age, 14 foals were housed in stalls and not exercised, 14 foals were housed in stalls and exercised daily, and 15 foals were maintained at pasture. Eight foals in each group were euthanatized at 5 months, and remaining foals were housed together in a stall and paddock until euthanatized at 11 months. After euthanasia, SDFT were isolated and fit in a material testing system. Mean cross-sectional area (CSA) was measured and traction forces recorded. Normalized force at rupture (force(rup)), normalized force at 4% strain, strain at rupture, stress at 4% strain (stress(4%stain)), and stress at rupture were compared among and within groups.


RESULTS
At 5 months, mean CSA and normalized force(rup) were significantly greater and stress(4%strain) significantly less in the pastured group, compared with the other groups. At 11 months, CSA and normalized force(rup) were not significantly different among groups, because force(rup) increased significantly from 5 to 11 months in the nonexercised group and decreased significantly in the pastured group.


CONCLUSIONS
Exercise significantly affected the biomechanical properties of the SDFT in foals. Evenly distributed moderate- and low-intensity exercise at a young age may be more effective for development of strong, flexible tendons in horses than single episodes of high-intensity exercise superimposed on stall rest. This effect may impact later susceptibility to SDFT injury.
Cherdchutham
W
W
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Meershoek
L S
LS
van Weeren
P R
PR
Barneveld
A
A
D000818:Animals; D000831:Animals, Newborn; D006736:Horses / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D013710:Tendons / Q000502:physiology*