Abnormalities of the Soleus H-Reflex in Lumbar Spondylolisthesis: A Possible Early Sign of Bilateral S1 Root Dysfunction

Changes in coordination of postural control during dynamic stance in chronic low back pain patients

“…It is possible that a change in proprioceptive feedback from segments of the body other than the trunk may also influence postural control in CLBP patients. Interestingly, an increased electrical threshold for activation of the largest sensory fibres conveying proprioceptive information from the soleus muscle has been observed in a group of patients with CLBP due to spondylolisthesis [25,26]. Sensory dysfunction such as this may increase the threshold to movement detection at the level of the ankle joint.…”

“…In this strategy, the muscles groups acting at the ankle joint are considered as the main musculature for the control of stability during quiet standing [24]. Patients with CLBP due to spondylolisthesis have been found to have abnormalities of the soleus H-reflex [25,26] which depends on the activation of large-diameter mechano-receptive afferents (group Ia fibres) in the muscle [27]. It is known that changes in Ia input may result in altered proprioception [28] and distortion of sensory maps [29].…”

Short-Term Effects of Spinal Manipulation on H-Reflex Amplitude in Healthy and Symptomatic Subjects

“…Alterations of the H-reflex amplitude, latency, or even absence of the H-reflex response have been observed in patients with S1 root dysfunction. 1,8 Others observed changes in H-reflex responses in patients with spinal cord injuries and suggested that the spinal reorganization and the associated decrease in presynaptic inhibition may be responsible for these changes. 9 These studies suggest that pathological changes in the neural system are reflected by altered H-reflex responses.…”

Recruitment curve of the soleus H-reflex in chronic back pain and lumbosacral radiculopathy

“…Needle EMG, which tests only ventral root function, may be normal in the absence of motor symptoms[3]. We have recently reported prolongation of the latency of the soleus H-reflex as the only abnormality revealed by standard electrodiagnostic procedures in patients with lumbar spondylolisthesis[4]. This finding implies that the H-reflex test is an essential diagnostic criterion for radiculopathy, especially when clinical and electrophysiological signs of motor root involvement are lacking.…”