Autonomic nervous system function among individuals with acute musculoskeletal injury.
OBJECTIVE
To determine differences in peripheral and cardiovascular autonomic function between individuals with acute musculoskeletal injury (<1 week) and healthy controls.


METHODS
Autonomic cardiovascular modulation, baroreceptor sensitivity, skin conductance, and peripheral skin temperature were obtained in 6 subjects with acute musculoskeletal injury and 6 age- and sex-matched controls. Power spectral analysis was performed on both beat-to-beat R-R intervals and continuous systolic blood pressure (SBP) peaks. Baroreceptor sensitivity was derived using both heart rate and blood pressure spectral analysis components.


RESULTS
The SD of R-R intervals was significantly different for the acute injury group relative to controls (49.8 +/- 10.5 vs 76.8 +/- 12.7 ms; P < .01). Continuous SBP peaks and skin conductance (sympathetic vasomotor and sudomotor indices, respectively) were significantly higher (59.6 +/- 6.7 vs 23.8 +/- 6.4 mm Hg2 /Hz, and 3.87 +/- 1.04 vs 2.19 +/- 0.3 mhos; P < .01, respectively) and baroreceptor sensitivity lower (0.97 +/- 0.07 vs 1.10 +/- 0.08 mm Hg; P < .02) in the acute injury group compared with controls. Regression analysis revealed a significant relationship between skin conductance and continuous SBP peaks (r = 0.75; P < .01).


CONCLUSIONS
These findings suggest that interaction between cutaneous and vasomotor sympathetic neurons in response to acute musculoskeletal injury, reflected as increased afferent input from sensitized nociceptors and other sensory neurons, results in alterations in autonomic function.
Grimm
David R
DR
Department of Basic Science and Clinical Science & Research, New York Chiropractic College, Seneca Falls, NY 13148, USA. dgrimm@nycc.edu
Cunningham
Brian M
BM
Burke
Jeanmarie R
JR
D000208:Acute Disease; D000328:Adult; D001341:Autonomic Nervous System / Q000503:physiopathology*; D019567:Back Injuries / Q000503:physiopathology*; D017704:Baroreflex; D001794:Blood Pressure; D002319:Cardiovascular System / Q000294:innervation*; D005260:Female; D005712:Galvanic Skin Response; D006339:Heart Rate; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology*; D008297:Male; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement