Benefits of Training the Iron Cross With Herdos Devices and External Load Added to Body Weight for Young Nonachiever Gymnasts.

Purpose: To verify whether training the iron cross (IC) with assistive devices (herdos; H_IC) and added external load (LH_IC) to equate the moments of force developed on the rings could be considered an intermediate step between the nonoverloaded herdos situation (H_IC) and the IC performed on the rings. Methods: Relative levels of surface electromyography (sEMG) activity were normalized with respect to a standing IC before comparing gymnasts who can perform the IC on the rings (achievers) and gymnast who cannot (nonachievers) in the 2 herdos conditions (H_IC and LH_IC). Seven muscles were chosen for sEMG analysis, namely, pectoralis major (PM), latissimus dorsi, teres major, lower trapezius, serratus anterior, biceps brachii (BB), and triceps brachii. Additionally, 3 indices were calculated to measure levels of coactivation: Elbow_idx, Scapula_idx, and Shoulder_idx. Results: The bigger magnitude of differences in sEMG activity among situations was found for the PM and BB (F ≥ 30.7; P <.001). When comparing the global and the PM, teres major, BB, and triceps brachii activity across groups, nonachievers activated their musculature to a greater extent than the achievers independently of the herdos situation (P ≤.046). Achievers' Elbow_idx was the only index that was significantly higher (P ≤.005) in the IC in comparison to LH_IC and H_IC. Conclusion: sEMG activity of PM and BB was particularly sensitive between situations, independently of the level of achievement. We recommend training the IC by adding external load in the herdos situation to increase muscle activity to levels closer to the rings situation but avoiding the potential factor of injuries. [ABSTRACT FROM AUTHOR]