title: THE EFFECT OF A PELVIC COMPRESSION BELT ON FUNCTIONAL HAMSTRING MUSCLE ACTIVITY IN SPORTSMEN WITH AND WITHOUT PREVIOUS HAMSTRING INJURY.
abstract: BACKGROUND
  There is evidence that applying a pelvic compression belt (PCB) can decrease hamstring and lumbar muscle electromyographic activity and increase gluteus maximus activity in healthy women during walking. Increased isokinetic eccentric hamstring strength in the terminal range (25 ° - 5 °) of knee extension has been reported with the use of such a belt in sportsmen with and without hamstring injuries. However, it is unknown whether wearing a pelvic belt alters activity of the hamstrings in sportsmen during walking.
  
  
  OBJECTIVE
  To examine the effects of wearing a PCB on electromyographic activity of the hamstring and lumbopelvic muscles during walking in sportsmen with and without hamstring injuries.
  
  
  METHODS
  Randomised crossover, cross-sectional study.
  
  
  METHODS
  Thirty uninjured sportsmen (23.53 ± 3.68 years) and 20 sportsmen with hamstring injuries (22.00 ± 1.45 years) sustained within the previous 12 months participated in this study. Electromyographic amplitudes of the hamstrings, gluteus maximus, gluteus medius and lumbar multifidus were monitored during defined phases of walking and normalised to maximum voluntary isometric contraction. Within-group comparisons [PCB vs. no PCB] for the normalised electromyographic amplitudes were performed for each muscle group using paired t tests. Electromyographic change scores [belt - no belt] were calculated and compared between the two groups with independent t tests.
  
  
  RESULTS
  No significant change was evident in hamstring activity for either group while walking with the PCB (p > 0.050). However, with the PCB, gluteus medius activity (p ≤ 0.028) increased in both groups, while gluteus maximus activity increased (p = 0.025) and multifidus activity decreased (p < 0.001) in the control group. The magnitude of change induced by the PCB in gluteus medius activity was similar between groups (p = 0.760). No statistically significant baseline differences in no belt scores were evident between groups for the investigated muscles (p ≥ 0.050).
  
  
  CONCLUSIONS
  Application of a PCB had individual-specific effects on electromyographic activity of injured and uninjured hamstrings during walking, resulting in no significant changes within or between the two groups. Future studies investigating effects of the PCB on hamstring activity in participants with acute injury and during a more demanding functional activity such as running are warranted.
  
  
  METHODS
  Level 3.
authors.forename: Ashokan
authors.initials: A
authors.lastname: Arumugam
authors.affiliation: School of Physical Therapy, University of Saskatchewan, Canada.
authors.forename: Stephan
authors.initials: S
authors.lastname: Milosavljevic
authors.affiliation: Department of Anatomy, University of Otago, New Zealand.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Woodley
authors.affiliation: Centre for Health, Activity and Rehabilitation Research, School of Physiotherapy, University of Otago, New Zealand.
authors.forename: Gisela
authors.initials: G
authors.lastname: Sole
keywords: Athletic injury; hamstring; orthotic; surface electromyography; walking