Stretch Reflex of Paraspinal Muscles in Normal Man and Hemiplegics
Methods for obtaining the stretch reflex of paraspinal muscles are described in a study of the SRPM in 20 normal, 20 right hemiplegic and 20 left hemiplegic subjects. In order to prevent superimposition with the EKG, the EKG R-wave was used to trigger the magnetic hammer which induced the SRPM by tapping at a point between L-l and L-2. The SRPM was recorded from leads attached bilaterally at levels L-3, L-l, T-8 and T-6. The SRPM was influenced significantly by posture, and in the standing posture. Right and left hemiplegics showed a reciprocal pattern. Possible explanations of why the SRPM was not exaggerated in hemiplegics are discussed.