Force irradiation effects during upper limb diagonal exercises on contralateral muscle activation

Abstract

The aim of this study was to explore the force irradiation effects of upper limb isometric diagonal exercises on shoulder muscle activities. Interactions among diagonal directions, contraction intensities (moderate and maximum) and sex were assessed. Thirty healthy subjects (11 males) performed isometric unilateral diagonal exercises based on proprioceptive neuromuscular facilitation technique in an isokinetic dynamometer with their dominant upper limbs. The second diagonal for flexion and for extension were assessed while the participants performed their maximum isometric torque (MIT) and at 25% of their MIT. During the exercise the muscle activity of the medial deltoid, pectoralis major and upper trapezius in the non-dominant (non-exercised) upper limbs of the participants was recorded by surface electromyography. The highest muscle activity occurred in the upper trapezius during the diagonal for flexion (27% of maximum isometric voluntary contractions). Upper trapezius and pectoralis major were more active during the diagonal for flexion than diagonal for extension (p < 0.001), while similar values between both diagonals were observed for the medial deltoid (p > 0.05). In conclusion, we observed that force irradiation during upper limb diagonal exercises is affected by diagonal direction, contraction intensity and sex when performed by healthy participants.

Overflow of Muscle Activation by Proprioceptive Neuromuscular Facilitation in Standing Position: A Cross-Sectional Electromyographic Investigation in Healthy Individuals

“…In addition, another study showed that force irradiation during upper limb diagonal exercises is affected by diagonal direction, contraction intensity, and gender when performed by healthy participants [5]. Our results in a previous article [6] match with some of these ndings.…”

“…The data normality was tested and con rmed by the Kolmogorov-Smirnov test. We used a repeated-measures ANOVA test for each muscle in different tasks that were applied [muscle x (5…”

Comparison of abdominal muscle activity during abdominal drawing-in maneuver combined with irradiation variations

“…When it is difficult to train the injured areas directly in sport rehabilitation, the cross training that improves strength of injured part using the opposite part is a form of irradiation (Abreu et al, 2015; Kofotolis and Kellis, 2007; Reznik et al, 2015). The mechanism is uncertain and may be caused by the bilateral distribution of the descending motor pathways, neural overflow and muscular system (Kofotolis and Kellis, 2007; Røe et al, 2000).…”

Motor Irradiation According to the Concept of Proprioceptive Neuromuscular Facilitation: Measurement Tools and Future Prospects

“…Irradiation is governed by the principle of training specificity (isometric or dynamic), and eccentric contractions cause greater strength gains when compared to concentric contractions [7,8]. This strength gain can be propagated to the ipsilateral agonist muscle, to contralateral limb [9] or having origin in trunk and irradiate for the lower and / or upper limbs [10].…”

“…Several authors used electromyography (EMG) to evaluate the irradiation produced by PNF because is possible to record the activity of motor units that are recruited during muscle contractions [7,14,9]. The effects of PNF in the brain is evaluated using the Functional magnetic resonance imaging (fMRI), a tool also a lot highlighted in the studies of PNF [14].…”