title: Neurophysiologic influences on hamstring flexibility: a pilot study.
abstract: OBJECTIVE
  To examine the potential contribution of neurologic influences on hamstring length during passive range of motion.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Academic sports medicine center.
  
  
  METHODS
  15 subjects undergoing arthroscopic surgery for unilateral knee injuries without previous injury to the contralateral knee.
  
  
  METHODS
  Subjects received: 1) spinal anesthesia with bupivacaine, 2) epidural anesthesia with lidocaine, 3) general anesthesia, or 4) femoral nerve block of injured leg only.
  
  
  METHODS
  Noninjured leg popliteal angle preoperatively, intraoperatively under anesthesia, and postoperatively after recovery from anesthesia.
  
  
  RESULTS
  The overall mean popliteal angle was 132.5 +/- 3.1 degrees preoperatively, 134.31 +/- 11.6 degrees intraoperatively, and 130.7 +/- 10.2 degrees postoperatively. Overall, the intraoperative angle was significantly greater than the postoperative angle (p = 0.02). The mean change in popliteal angle was 8.1 +/- 2.2 degrees (Group 1), -0.4 +/- 1.9 degrees (Group 2), 0.9 +/- 1.4 degrees (Group 3), and -2.4 +/- 3.8 degrees (Group 4). There was no significant change in pre- to postoperative popliteal angle in relation to postoperative pain. Females had a greater mean popliteal angle (139.84 degrees ) compared with males (128.84 degrees ) (p = 0.04).
  
  
  CONCLUSIONS
  Understanding the neuromuscular influences on muscle flexibility will assist in the development of new rehabilitative and injury preventative techniques.
  
  
  CONCLUSIONS
  The present pilot study implicates neural contributions to muscle flexibility. Further studies are needed to delineate the relative contributions of neural and muscular components and to facilitate new techniques in the rehabilitation and prevention of injury.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Johns Hopkins Hospital, Baltimore, Maryland, USA. bkrabak@jhmi.edu
authors.forename: B J
authors.initials: BJ
authors.lastname: Krabak
authors.forename: E R
authors.initials: ER
authors.lastname: Laskowski
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: M J
authors.initials: MJ
authors.lastname: Stuart
authors.forename: G Y
authors.initials: GY
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001265:Athletic Injuries / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007596:Joints / Q000503:physiopathology*; D007866:Leg / Q000503:physiopathology; D007869:Leg Injuries / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D010147:Pain Measurement; D010149:Postoperative Pain; D010865:Pilot Projects; D018583:Pliability; D011184:Postoperative Period; D011300:Preoperative Care; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012737:Sex Factors; D013223:Statistics as Topic