Affiliations: [a] Exercise and Sports Science Program, The University of
Tulsa, Tulsa, OK, USA
Note: [] Corresponding author: John Caruso, 800 S. Tucker Drive, The
University of Tulsa, Tulsa, OK 74104, USA. Tel.: +1 918 631 2924; Fax: +1 918
631 2068; E-mail: john-caruso@utulsa.edu
Abstract: Our study assessed motor unit behavior and muscle function from
high-speed unilateral elbow flexor workouts. Electromyography and performance
data were obtained from subjects who completed three workouts on an Impulse
(Impulse Training Systems; Newnan, GA) exercise machine. Comprised of both
tonic and phasic repetitions, workouts were done with three different loads
(1.13, 3.4 and 6.8 kg) added to the machine. Electromyography was measured from
three muscles (biceps brachii, triceps brachii, brachioradialis). Dependent
variable means, obtained as the elbow flexed and extended, were compared with 2
(tonic, phasic) x2 (men, women) x3 (1.13, 3.4 and 6.8 kg) ANOVAs, with repeated
measures for repetition and load. Bonferroni's adjustment preserved family-wise
error rates and t-tests served as a post-hoc. With α=0.05, several
dependent variables displayed intra-repetition and -load effects. However
triceps root mean square (RMS) values displayed repetition x load interactions
for both elbow flexion and extension. The triceps, an elbow flexion antagonist,
may act as an important joint stabilizer, particularly at faster velocities and
more extended joint angles. Unlike isometric or standard low-velocity paradigms
performed against heavy loads, high-speed exercise may entail a more equitable
distribution among factors (motor unit recruitment, rate coding, reflex
potentiation, antagonist co-contraction) responsible for current triceps RMS
values.
Keywords: Triceps, root mean square, brachioradialis
