Application of the chemical irritant mustard oil to the hind limb of anaesthetized rabbits can produce long-lasting increases in withdrawal reflexes which are dependent on the reflex studied and the location of the noxious stimulus (Harris & Clarke, 2003). These previous studies recorded EMG responses, so alterations in hind limb movements were implied rather than actually observed. The aim of the present study was to use a movement analysis system to examine the effect of mustard oil on actual movements of the hind limb. Experiments were performed on 13 rabbits lightly anaesthetized by a continuous i.v. infusion of Saffan (between 12 and 46 mg kg-1 h-1). Withdrawal responses in the left hind limb were evoked by noxious pinch of the skin using toothed forceps fitted with a pressure transducer (mean force 1.5 ± 0.2 kg for 1.4 ± 0.2s). Stimuli were randomly applied to eight locations but only data in response to pinching the ipsilateral heel or toes are included here. Movements of the limb were measured using a CODAmotion movement analysis system which allowed 3D joint angles at the hip, knee and ankle to be calculated via detection of strategically located infra-red emitters. Following recording of control responses a mustard oil conditioning stimulus (50μl; 20% in paraffin oil) was applied to one of six locations (maximum of three sites per animal) and pinch-evoked movements subsequently obtained. Only data after mustard oil application to the heel or the plantar MT joints are reported. In animals receiving mustard oil to the heel, the control response to noxious pinch at the heel was extension of the ankle (by 4.8 ± 1.4 degrees, mean ± S.E.M.) and flexion at the knee and hip (by 6.4 ± 2.1 and 4.7 ± 1.6 degrees, respectively). After application of mustard oil to the heel, extension at the ankle joint in response to heel pinch was significantly increased (paired t-test, p < 0.05; n = 8) to a mean of 9.7 ± 2.0 degrees, but flexion at the knee or hip joints was not significantly altered reaching 6.8 ± 1.1 and 6.4 ± 1.3 degrees, respectively. In animals receiving mustard oil to the MT joints, the control response to noxious pinch at the toes was usually flexion at all three joints: mean angle changes at the ankle, knee and hip were 2.7 ± 0.7, 3.9 ± 1.6 and 1.6 ± 0.9 degrees, respectively. Application of mustard oil to the MT joints led to a significant increase in flexion at both the ankle and knee joints in response to toe pinch (paired t-tests, p < 0.05; n = 7): post-mustard oil angle changes were 7.6 ± 1.6, 9.0 ± 1.5 and 3.3 ± 0.9 degrees at the ankle, knee and hip respectively. These data show that a noxious conditioning stimulus can facilitate certain movements of the hind limb to pinch stimuli. In support of previous findings, the increases appear to enhance the protective function of the movement.