Facilitation of the isometric maximum voluntary contraction with traction. A test of PNF predictions Academic Article uri icon


  • Mean rectified electromyographic activity in vastus lateralis (VL) was recorded with surface electrodes during several Ss isometric maximum voluntary contractions performed in the PNF pattern of flexion-abduction-internal rotation, with the subject supine. The effects of longitudinally applied traction forces were compared in a within subject design employing latin square and counterbalanced presentation. Consistent with predictions, as traction force increased the group mean EMG showed a statistically significant increase. A brief survey using force platform measurements indicated that trained physical therapists tended to apply equal or greater forces than the 20 lb maximum used in the experiment.

publication date

  • February 1, 1983