Shoulder Muscle Activation Levels During Four Closed Kinetic Chain Exercises With and Without Redcord Slings

Abstract

During resistance training protocols, people are often encouraged to target the scapular stabilizing musculature (middle and lower trapezius and serratus anterior) while minimizing shoulder prime mover activation (upper trapezius and large glenohumeral muscles) in their training regime, especially in overhead athletes with scapular dyskinesis. To increase the activation levels in the stabilizing muscles without drastically increasing the activation in the prime movers, unstable surfaces are frequently used during closed kinetic chain (CKC) exercises. However, the specific influence of Redcord slings (RS) as an unstable surface tool on the shoulder muscle activation levels has rarely been investigated, despite these results may be used for adequate exercise selection. Therefore, a controlled laboratory study was performed on 47 healthy subjects (age, 22 ± 4.31 years; height, 176 ± 0.083 cm; weight, 69 ± 8.57 kg) during 4 CKC exercises without and with RS: half push-up (HPU), knee push-up (KPU), knee prone bridging plus (KPBP), and pull-up. When using RS, serratus anterior muscle activation decreased during the KPU and KPBP exercise. In addition, a drastic increase in pectoralis major muscle activation was found during the HPU and KPBP exercise. Consequently, the use of RS does not necessarily imply that higher levels of scapular stabilizer muscle activation will be attained. These findings suggest that RS might be an appropriate training tool when used within a general strengthening program but should not be preferred over a stable base of support when training for specific scapular stabilization purposes.

Serratus Anterior and Upper Trapezius Electromyographic Analysis of the Push-Up Plus Exercise: A Systematic Review and Meta-Analysis

“…Seven articles discussed the effects of PUP variations (eg, different upper extremity, 31,47,48,50 lower extremity, 29,49 and PUP 8 positions) on training the SA and UT. Eleven articles 9,[15][16][17][18][19][20][21][22][23]52 focused on the effects of the base of support for PUP exercises. From our systematic review, we determined a suitable exercise prescription for training the SA and UT using PUP variations.…”

“…Twelve articles focused on the effects of the base of support during PUP exercises. 9,[15][16][17][18][19][20][21][22][23]51,52 After further checking for the meta-analysis, 1 article was excluded due to insufficient data for the means and standard deviations. 51 Therefore, 11 articles were included in this meta-analysis for analyzing the differences in SA and UT muscle activity during the PUP performed on stable and unstable surfaces.…”

“…51 Therefore, 11 articles were included in this meta-analysis for analyzing the differences in SA and UT muscle activity during the PUP performed on stable and unstable surfaces. 9,[15][16][17][18][19][20][21][22][23]52 Quality Assessment…”

“…[12][13][14] After finding that the standard PUP (SPP) and knee PUP exercises induced the highest SA and lowest UT : SA EMG measures, Ludewig et al 8 recommended these exercises for selective SA strengthening. Researchers 5,9,[15][16][17][18][19][20][21][22][23][24][25][26] have investigated whether the PUP exercise performed on different unstable bases stimulated mechanoreceptors and increased SA EMG activity, thereby enhancing shoulder-joint stabilization. The use of unstable or stable surfaces during the PUP exercise is under debate.…”

Scapular Dyskinesis: From Basic Science to Ultimate Treatment

“…Scapular stabilization exercises are based on closed and open kinetic chain exercises, including push-ups on a stable or unstable surface, lawnmower exercises and resisted scapular retraction [26,136] (Figure 4). Push-ups on a stable surface improve the serratus anterior stretch and, when Red Cord slings are used, general muscle strength improvements are obtained [137]; the same exercise, performed on an unstable surface, increases the activation of the trapezius, while decreasing the activation of the serratus anterior [138]. The upper and lower trapezius muscles can be better stimulated with upward rotation shrugs [139].…”