A farrier at the Royal Veterinary College in England examined the effects of tungsten road nails on movement asymmetry using wireless inertial measurement devices that measure vertical movement.

The nails were randomly placed one at a time in the left and right lateral heels of both front and hind hooves. The horses were jogged on an asphalt surface during the study with differences in head and pelvic movement asymmetry before and after application compared with a zero value (no difference).

After application of the tungsten heel-nail to the left hind limb, left to right pelvic movement was significantly more negative, indicating more right-sided movement amplitude. No other movement asymmetries were noted at the poll, withers or sacrum following placement of the road nails. These results indicate that a tungsten road nail in the lateral heel produces a small increase in hind limb weight-bearing and propulsion in the treated limb compared with the opposite limb without the added traction device.

The authors suggest further work is needed to investigate the effects of tungsten road nails on hoof slip and grip, as well as the possible long-term effects of this type of traction device.

— Day P et al. JEVS 2020;90:103000