Fig 1.
Example of anterior and posterior muscle chain interaction during a giant swing bwd.
A lattice model, based on the original kinematic data of a gymnast, is shown with the onsets of the EMG data integrated as colored matrices. During the performance of a giant swing bwd the EMG of the anterior muscle chain (colored in red) was captured from pectoralis major (PM), rectus abdominis (RA) and rectus femoris (RF) and of the posterior muscle chain (colored in blue) from deltoideus, lateral part (DL), erector spinae (ES), and biceps femoris (BF). The direction of neuromuscular onset (and offset) succession is highlighted by black circles. For better demonstration of the overlapping nature of the “spreading” and “recurring” neuromuscular activation, the anterior and posterior muscle chain are each depicted in a separate drawing. For better graphic demonstration and for avoiding overlapping of the positions, the rotational axis is depicted in various positions (the arrows indicate the movement direction). The elected kinematic positions represent each the first frame after the crossing of the onset or offset threshold. See text for more details.
Fig 2.
Examples of INOS patterns for generation of whip like leg acceleration phases (LAP) during long hang elements on high bar.
The upper row of the figure demonstrates the complete element based on original kinematic data of a gymnast (the arrows indicate the movement direction). The sectors between the dotted lines shall give readers an orientation of the phase of interest (“leg acceleration phase”, each marked by a dynamic change of a body position, slightly curved to backward (“C-minus” position) to a position, slightly curved to forward (“C-plus” position; see methods). The second row in the figure specifically focuses to the INOS patterns for generating the acceleration phase (running from punctum fixum to punctum mobile; highlighted by black circles), with the positions elected of each the first frame after crosssing the onset threshold. The third row shows each the original EMG data of the demonstrated trial, with the onset thresholds (20% treshold line; see methods) connected by dotted lines (the numbers 1, 2 and 3 correlate with the positions as demonstrated in the lattice models above). On each the left side of the EMG plots the color scale is represented, the colored muscle matrices in the segment models of the second row are based on. The colors in the segment models are The last row (at the bottom of the figure) shows the kinematic angle–time characteristics during the movements of the shoulder angle (measured between upper body and upper arms), the angle of pelvis tilt, which is induced by the sagittal movement of the lumbar spine (LS; angle between upper body and pelvis segment) and the hip angle (measured between pelvis segment and thigh). The data is synchronized with EMG based on a frequency of 50Hz. For better demonstration of the intersegmental kinematic succession the integrated dotted lines each connect the onsets (beginning) of the angle changes (first dotted line) and the maximum of the angles (second dotted line). The fact that these lines run inversely (from the punctum mobile to the punctum fixum) than the dotted lines of the neuromuscular onsets (from the punctum fixum to the punctum mobile) demonstrate that the direction of the intersegmental kinematic succession does not correlate with the direction of the intersegmental neuromuscular succession.
Fig 3.
Examples of interactions between the INOS patterns of the anterior and posterior muscle chain during different long hang elements.
In the two upper rows the figure demonstrates typical INOS patterns of momentum transfer phases (MTP) during different elements on high bar (HB) and parallel bars (PB)—and additionally, in the lower two rows of the figure it gives an overview about the typical interactions between the anterior and posterior muscle chain during the acceleration phase that is directly followed by the momentum transfer phase, as depicted above. The upper row of the figure shows the complete element based on original kinematic data of a gymnast (the arrows indicate the movement direction). The sectors between the dotted lines shall give readers an orientation of the phase of interest (momentum transfer phase, each marked by a dynamic change of from “C-plus” position (body position slightly curved to forward) to “C-minus” position (slightly curved to backward; see methods). The second row in the figure specifically focuses to the INOS patterns of the MTP (running back from punctum mobile to punctum fixum; highlighted by black circles), with the positions elected of each the first frame after crosssing the onset threshold (see methods). The third and last rows (EMG plots) show each the original synchronized EMG data of the demonstrated trials, with the onset and offset thresholds of the anterior (third row) and posterior (fourth row) muscle chain during the movement (LAP: Leg acceleration phase; MTP: Momentum transfer phase; CAP: Counter-acceleration phase). The dotted lines in the EMG plots connect the crossing points of the EMG signal with the 20% threshold for the onset and offset detection, generating a “double V” constellation that is typical in movements with accceleration phases followed by a transfer of momentum phase. This demonstrates the typical overlapping characteristics of “spreading and “recurring” patterns of the neuromuscular activation (compare also Fig. 1). Only the “Tkatchev 2” shows a deviation of this “double V” constellation (see text for more details).
Fig 4.
Lattice models of exemplary original kinematic data of all 19 elements.
The sectors between the dotted lines of each element approximately represent the phase during which an actively performed acceleration of the punctum mobile takes place. In movement 19, the lower row shows the frontal view, the upper row shows the top perspective.
Fig 5.
Detection and appellation of the INOS patterns.
a) Demonstration of the angles between segmentum fixum and segmentum mobile in the C-minus vs. C-plus position. b) Onset detection: Right: EMG of the anterior muscle chain with m. pectoralis major (PM; M1), m. rectus abdominis (RA; M2) and m. rectus femoris (RF; M3) during a giant swing. The horizontal lines in the plots represent the onset threshold. Their first crossing with the EMG activation is defined as the ‘‘onset time”. On the left side of the EMG plots the color scale is represented, the colored muscle matrices in the segment model are based on. Left: Lattice model of the gymnast (with muscle matrices integrated) at the moment been represented by the vertical line of the EMG on the right. c) Examples of dynamic changes from C-minus to C-plus positions (or vice versa) during different elements around different axes. The appellation of the corresponding muscles depends on the location of the rotational axis (M1 allways next to punctum fixum).
Table 1.
Overview of the analyzed movements.
Table 2.
Muscles and functions.
Fig 6.
Mean ± standard deviations within the different movement groups.
The data refer to the onset times related to muscle 1 (M1) for generating the acceleration phases, according to the six groups as defined in Table 1.
Fig 7.
Mean ± standard deviations within the different elements.
The data refer to the onset times related to the muscle 1 (M1) for generating the acceleration phases, according to the element numbers as defined in Fig. 1. HB: high bar; PB: parallel bars. For better readability, some of the elements were combined into one bar in the figure.
Table 3.
Descriptive analysis of the percent of individual counts of demonstrated patterns within the six element groups per subject.
Fig 8.
Examples of original data gathered during some movements of the present study.
The top row shows the complete element based on original kinematic data of a gymnast (arrows indicate movement direction). The second row shows the INOS patterns for generating the acceleration phases (from punctum fixum to punctum mobile), with the positions selected of the first frame after crossing the onset threshold (see methods). On each the left side of the EMG plots the color scales are represented, the colored muscle matrizes in the segment models of the second row are based on. The bottom row shows the original EMG data of the demonstrated trial. The dotted lines in the EMG plots connect the crossing points of the EMG signal with the 20% threshold line to better clarify the patterns of the intersegmental neuromuscular onset succession (1, 2, and 3 correlate with the positions in the lattice models above). Upper plot: upper extremities (PM/DL); middle plot: mid body (RA/ES); additionally, for a better depiction in the frontal view of the presented pivot movement (floor), also the left and right musculus obliqui externi were captured in that example; lower plot: lower extremities (RF/BF). Depending on the location of the rotational axis (punctum fixum) the onsets run from the hands to the feet (during elements with punctum fixum = hands) or from the feet to the hands (during elements with punctum fixum = feet).
Fig 9.
Efficient vs. inefficient INOS patterns.
On the left side of the figure, the angles between the segmentum fixum and segmentum mobile (C-minus vs. C-plus position) are schematically depicted during an efficient INOS activation from punctum fixum to punctum mobile (pattern 1-2-3). On the right side several examples of inefficient INOS patterns are demonstrated. All these patterns result in a diminished angle between segmentum fixum and segmentum mobile. Additionally, the drawings demonstrate the resulting deviations of body segments, caused by deviating INOS patterns, as listed in the bottom line.