Effect of Joint Traction and Approximation on H-Reflex in Normal Subjects

Introduction: Proprioceptive sensation (kinaesthesia and/or joint position sense), one of the most important somatosensory modalities, is known to play an important role in body balance and motor control. Joint traction and approximation are two proprioceptive stimuli applied at the joint. Studies reveal that an unidentified set of muscle afferent fibres and cutaneous receptors both contribute to the sense of movement and position. The Hoffmann reflex (H- reflex), an electrically evoked monosynaptic reflex, is a measure of the final common pathway, or the motor output.

Objective: To find out the effect of traction and approximation on H-reflex.

Method: Study performed on 20 normal subjects both males and females taken from the city Anand under the age group of 19-26 years. This is an experimental study, which is performed in the clinic of physiotherapy. The subject was made to lie prone comfortably on a plinth. The tibial nerve was stimulated at the popliteal fossa using 1 ms pulse and then finds H- latency and amplitude of Hwave. The subject was made to stand on the wooden board with same electrode arrangement to approximate the articular surfaces of the knee joint. The procedure was repeated to find H- latency, and amplitude of H- wave. The subject was made to sit on the stool with same electrode arrangement and right leg hanging freely off the stool. A 2 kg weight was tied at the ankle to distract the knee joint. The procedure was repeated to find H- latency, and amplitude of H- wave.

Results: There is significant difference in H-reflex latency and amplitude in prone, joint traction and approximation.

Conclusion: There is significant change in latency with proprioceptive input.