PMID- 20531355
OWN - NLM
STAT- MEDLINE
DCOM- 20111129
LR  - 20110107
IS  - 1476-5624 (Electronic)
IS  - 1362-4393 (Linking)
VI  - 49
IP  - 1
DP  - 2011 Jan
TI  - Muscle fatigue characteristics in paralyzed muscle after spinal cord injury.
PG  - 125-30
LID - 10.1038/sc.2010.62 [doi]
AB  - STUDY DESIGN: The study design used is cross-sectional. OBJECTIVES: The aim of 
      this study is to examine muscle contractile and excitability characteristics 
      during fatigue of the tibialis anterior in six individuals with chronic spinal 
      cord injury (SCI) and matched able-bodied (AB) controls. SETTING: McMaster 
      University, Hamilton, ON, Canada. METHODS: Muscle compound action potential 
      (M-wave) characteristics, muscle twitch properties, and summated force were 
      examined during a 2 min fatigue protocol of intermittent bursts at 30 Hz (4 s 
      tetanus, 2 s rest) or maximal voluntary contraction (MVC). Evoked twitch 
      responses were followed during a recovery period. RESULTS: M-wave amplitude was 
      smaller in SCI (2.5 +/- 1.6 mV in SCI, 5.7 +/- 3.2 mV in AB) at baseline, but there 
      was no change in M-wave amplitude or area during fatigue in either group. There 
      was an increase in M-wave duration toward the end of recovery in the SCI group. 
      Peak torque (PT) was not different between groups at baseline (3.8 +/- 1.8 Nm in 
      SCI, 3.7 +/- 0.6 Nm in AB); PT potentiated significantly during fatigue in the AB, 
      but not SCI group. There was significantly greater fatigue of both PT (43% 
      decline) and summated force (57% decline) in the SCI group compared with the AB 
      group (13% increase and 22% decline for PT and MVC, respectively). CONCLUSION: 
      The dorsiflexor muscles in people with SCI are significantly more fatiguable than 
      those in AB controls, but decreases in muscle excitability do not seem to be an 
      important contributor to the increased fatiguability. The mechanisms behind the 
      increased fatigue must lie distal to the muscle membrane.
FAU - Pelletier, C A
AU  - Pelletier CA
AD  - Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
FAU - Hicks, A L
AU  - Hicks AL
LA  - eng
PT  - Journal Article
DEP - 20100608
PL  - England
TA  - Spinal Cord
JT  - Spinal cord
JID - 9609749
SB  - IM
MH  - Adult
MH  - Cross-Sectional Studies
MH  - Female
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Muscle Fatigue/*physiology
MH  - Muscle Weakness/*diagnosis/etiology
MH  - Muscle, Skeletal/innervation/*physiopathology
MH  - Paralysis/*etiology
MH  - Spinal Cord Injuries/*complications
EDAT- 2010/06/10 06:00
MHDA- 2011/12/13 00:00
CRDT- 2010/06/10 06:00
PHST- 2010/06/10 06:00 [entrez]
PHST- 2010/06/10 06:00 [pubmed]
PHST- 2011/12/13 00:00 [medline]
AID - sc201062 [pii]
AID - 10.1038/sc.2010.62 [doi]
PST - ppublish
SO  - Spinal Cord. 2011 Jan;49(1):125-30. doi: 10.1038/sc.2010.62. Epub 2010 Jun 8.