Enhancing the weight training experience: a comparison of limb kinematics and EMG activity on three machines

Abstract

The aim of the study was to compare the kinematics and the timing and amount of electromyographic (EMG) activity during the lat-pull down exercise performed on machines that afforded one, two, or three degrees of freedom for the movement. Seven healthy men (age 29.4 +/- 5.6 years) participated in the study. The exercise was performed with a 30% 1-RM load. Three types of machines with varying degrees of freedom were used: Type 1, the conventional device that restricted the movement to a frontal plane; Type 2, the addition of forearm supination-pronation; Type 3, the addition of forearm supination-pronation and horizontal extension-flexion about the shoulder. All exercises involved a technique known as beginning movement load (BML) training in which light loads are lifted with a relaxation-lengthening-shortening sequence of muscle activation. The Type-3 machine showed: (1) the greatest vertical displacement of the wrist (p < 0.05); (2) the greatest abduction-adduction displacement about the shoulder (p < 0.01); (3) the least flexion-extension displacement about the elbow joint (p < 0.01); (4) a peak vertical velocity for the shoulder that preceded (p < 0.01) those for the elbow and then wrist during the pull-down phase; (5) a progressive proximal-to-distal sequence of EMG activation involving the serratus anterior, posterior deltoid, latissimus dorsi, and triceps brachii muscles; (6) a reversal of the roles for biceps and triceps brachii during the pull-down phase. These results suggest that BML exercises with greater degrees of freedom can enhance the association between training actions and functional activities.

Exploring the effect of repeated-day familiarization on the ability to generate reliable maximum voluntary muscle activation

“…These MVC trials are similar to those often reported in the literature for these muscles (e.g. Potvin, 1997;Ervilha et al, 2005;Koyama et al, 2010;Oliver et al, 2011).…”

Muscle activity of the core during bilateral, unilateral, seated and standing resistance exercise

“…Free weight exercises increases the stabilization requirements of the joint compared to stable machine exercises (Garhammer 1981;Koyama et al 2010;McCaw and Friday 1994). However, not all free weight exercises are the same.…”

Performing pull-ups with small climbing holds influences grip and biomechanical arm action

“…To train their arm and finger capabilities, climbers usually perform pull-ups (Youdas et al, 2010). These exercises are also part of the usual training regimen for several other sports and previous analyses in the literature concerned non-climbers (Andersen, Fimland, Wiik, Skoglund, & Saeterbakken, 2014;Antinori, Felici, Figura, Marchetti, & Ricci, 1988;Koyama, Kobayashi, Suzuki, & Enoka, 2010;. One major difference between pull-ups for climbing objectives compared to fitness is the use of various types of grips, including gym bars, as well as large and small climbing holds.…”