Abdominal maximal voluntary contraction was performed with the back against the dynamometer performing maximal forward flexion.
Correspondingly, for MVC of the abdominal muscles, the subject was placed with the back towards the dynamometer and the pelvis against the plate.
Assessment was performed with both legs at 130° leg flexion and measured with a dynamometer (Baseline® Back-Leg-Chest Dynamometer; Fabrication Enterprises Inc., Elmsford, NY, USA).
We obtained isometric muscle strength during maximal voluntary contraction of abdominal and back muscles using a strain-gauge dynamometer (10).
Subjects were asked to stand on the leg dynamometer with a straight back, leaning on the wall and holding the bar hand with an overhand grip.
Leg and back strength was measured using a leg/back dynamometer (Gloria TTM 300 kg, Tokyo).
Maximal voluntary isometric contraction strength (MVC) was obtained for the lower back extensor muscles using a custom-built dynamometer with a strain gauge load cell (KIS-2, 2 KN, Vishay Transducers Systems).
For MVC of the back extensor muscles, the subject faced the dynamometer with the pelvis against a plate placed with the upper edge aligned with the iliac crest of the subject.
Main Outcome Measures: Surface electromyography was recorded for 4 pairs of homologous back muscles while the subjects performed, on a dynamometer, static trunk extension efforts.
The main objective of this pilot study was to examine the clinical potential of these different EMG parameters for assessing the back muscles of patients presenting idiopathic scoliosis, using a triaxial dynamometer allowing the measurement of asymmetric efforts during extension contractions.
