Pre-synaptic modulation of quadriceps arthrogenic muscle inhibition

Riann M. Palmieri, Arthur Weltman, Jeffrey E. Edwards, James A. Tom, Ethan N. Saliba, Danny J. Mistry, Christopher D. Ingersoll

Research output: Contribution to journalArticlepeer-review

63 Scopus citations


Arthrogenic muscle inhibition (AMI) impedes rehabilitation following knee joint injury by preventing activation of the quadriceps. AMI has been attributed to neuronal reflex activity in which altered afferent input originating from the injured joint results in a diminished efferent motor drive to the quadriceps muscles. Beginning to understand the mechanisms responsible for muscle inhibition following joint injury is vital to control or eliminate this phenomenon. Therefore, the purpose of this investigation is to determine if quadriceps AMI is mediated by a presynaptic regulatory mechanism. Eight adults participated in two sessions: in one session their knee was injected with saline and in the other session it was not. The maximum Hoffmann reflex (H-reflex), M-wave, reflex activation history, plasma epinephrine, and norepinephrine were recorded at: baseline, post needle stick, post lidocaine, and 25 and 45 min post effusion. Measures for the control condition were matched to the effusion condition. The percent of the unconditioned reflex amplitude for reflex activation history and the maximum H-reflex were decreased at 25 and 45 min post effusion as compared to measures taken at baseline, post needle stick, and post lidocaine (P<0.05). No differences were noted for the maximum M-wave or plasma epinephrine and norepinephrine levels in either the effusion or noneffusion admission (P>0.05). No differences were detected at any time interval for any measure during the control admission (P>0.05). Quadriceps AMI elicited via an experimental knee joint effusion is, at least in part, mediated by a presynaptic mechanism.

Original languageEnglish
Pages (from-to)370-376
Number of pages7
JournalKnee Surgery, Sports Traumatology, Arthroscopy
Issue number5
StatePublished - Jul 2005


  • Activation failure
  • Catecholamines
  • Quadriceps
  • Spinal reflex
  • Weakness


Dive into the research topics of 'Pre-synaptic modulation of quadriceps arthrogenic muscle inhibition'. Together they form a unique fingerprint.

Cite this