Between-day reliability of upper extremity H-reflexes.
H-reflexes are useful for evaluating the group Ia monosynaptic reflex excitability in the lower and upper extremities (UEs). However, there is no established between-day protocol for measuring H-reflex excitability in the UE extensor carpi radialis longus (ECRL). The purpose of this study was to develop a reliable protocol to measure the H-reflex excitability between-days for the ECRL, and the antagonist muscle, the flexor carpi radialis (FCR). H-reflex recruitment curves were recorded from eight healthy young subjects over 3 consecutive days in both muscles. Variables associated with the H-reflex excitability were measured: (a) maximum amplitude (Hmax); (b) gain (HGN); (c) threshold (HTH, visHTH, and sdHTH). All variables were normalized with respect to the M-wave. Within individual muscles, there were no statistically significant differences between-days for the group (p>0.05) and variables showed fair to good reliability (ICC=0.57-0.99). This method of reliably measuring H-reflex excitability within UE muscles will be useful for investigating the effects of pathology and rehabilitation on monosynaptic reflexes.
Stowe
Ann Marie
AM
Landon Center on Aging, University of Kansas Medical Center, 3599 Rainbow Boulevard, MS 1005, Kansas City, KS 66160, USA.
Hughes-Zahner
Laura
L
Stylianou
Antonis Pantakis
AP
Schindler-Ivens
Sheila
S
Quaney
Barbara Marie
BM
D000328:Adult; D003625:Data Collection; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006225:Hand / Q000502:physiology; D006801:Humans; D016014:Linear Models; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D011999:Recruitment, Neurophysiological; D015203:Reproducibility of Results; D020521:Stroke / Q000503:physiopathology; D034941:Upper Extremity / Q000502:physiology*