title: Facilitation of the isometric maximum voluntary contraction with traction. A test of PNF predictions.
abstract: 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.
mesh_terms: D000293:Adolescent; D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D007719:Knee Joint / Q000502:physiology; D007866:Leg; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D009119:Muscle Contraction; D010465:Perception; D005082:Physical Exertion; D026741:Physical Therapy Modalities; D011434:Proprioception; D014143:Traction