Studies of surface electromyography on the forearm muscles

Summary I Summary This work is related to the study of the forearm muscles trough multi channels surface electromyographic technique. From 10 to 16 voluntary subjects (all males of age between 25 and 36 years) were involved in the study. The muscles studied were: ξ Extensor carpi radialis (ECR) ξ Extensor digitorum comunis (EDC) ξ Extensor carpi ulnaris (ECU) ξ Flexor palmaris longus (FPL) The purpose was to assess muscle activity and fatigability during several types of voluntary contractions. The following table reports the muscle investigated in each contraction performed: Muscles and number of subjects investigated for each type of contraction studied. Type of contractions Number of subjects ECR EDC ECU FPL 1) Isometric selective contraction of the wrist extensors 16 X X X 2) Isometric hand gripping 16 X X X X 3) Isometric wrist extension 14 X X X 4) Isokinetic concentric wrist extension and flexion 10 X X X X 5) Isokinetic eccentric wrist extension and flexion 10 X X X X The whole experimental session was done at the Centre de Recerca en Enginyeria Biomedica (CREB) of Barcelone (Spain) and at the Mùtua Hospital of Terrassa (Barcelone, Spain) where I’ve worked for 6 months in order to prepare the experimental set-ups, the acquisition protocol described in this thesis, and to collect the data. The data were processed by means of specifically written Matlab® routines at the LISiN (Laboratorio di Ingegneria del Sistema neuromuscolare e della riabilitazione motoria) of Turin where this thesis has been written. Surface EMG signals were collected by means of adhesive arrays of 8 silver chloride electrodes (LISiN-SPES Medica) placed on the subject’s skin after localizing the optimal zone of detection by means of a non adhesive array of 8 silver electrodes (Ottino Bielettronica). Signals were collected in single differential mode and amplified by means of two 16-channels surface EMG amplifiers (EMG16, LISiN and Prima Biomedical & Sports), converted into digital signals with two acquisition boards (National Instruments DAQCARD™-6024E) and then stored in data files. The selective contractions (1) were performed without force feedback asking the subject to perform a contraction, with a medium level of force, in order to selectively activate one muscle only. The isometric hand gripping (2) and wrist extension (3) were performed at three fractions