Muscle synergies during bench press are reliable across days

Kristiansen, Mathias Vedsø; Samani, Afshin; Madeleine, Pascal; Hansen, Ernst Albin

doi:10.1016/j.jelekin.2016.06.004

Cited by 27 publications

(33 citation statements)

References 34 publications

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“…Intra-session factors for variability include natural trial-by-trial variability of performed movements [5]. On the other hand, inter-session variability not only considers the natural variability normally found in performed movements but also may include other factors such as slightly different electrode positioning [20] and other intrinsic differences in subjects that can change in time (e.g., recovery, adaptation, exercise, etc.). Assessing whether these sources of variability may influence the similarity of the extracted synergies (i) within the same session, (ii) across sessions, and (iii) across subjects is crucial to provide reliable assessments.…”

Section: Introductionmentioning

confidence: 99%

“…Several studies tried to quantify variability in various conditions, even in hardly comparable designs and topics. Different body segments and tasks were considered (including bench press in upper-limbs [20], level walking in lower-limbs [24], and a complex gymnastics motor task in upper and lower limbs [25]). Some studies analyzed differences between sessions (e.g., between two sessions [20]), some between subjects (6 healthy volunteers [24] and 9 gymnasts [25]), and some between different movement repetitions [24].…”

Section: Introductionmentioning

confidence: 99%

“…Taborri et al [24] analyzed the number of synergies and the quality of the reconstructed data using intra-class correlation (ICC) and coefficient of variation (CoV) of both global variance accounted for (VAF) and VAF of each muscle. Kristiansen [20], Frere, and Hug [25] compared time activations from two sessions while spatial composition was kept constant and vice versa. These studies conclude that, in general, variability is found intra-session and intra-subject as well as inter-subject.…”

Section: Introductionmentioning

confidence: 99%

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Variability of Muscle Synergies in Hand Grasps: Analysis of Intra- and Inter-Session Data

Pale

Atzori

Müller

et al. 2020

Sensors

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Background. Muscle synergy analysis is an approach to understand the neurophysiological mechanisms behind the hypothesized ability of the Central Nervous System (CNS) to reduce the dimensionality of muscle control. The muscle synergy approach is also used to evaluate motor recovery and the evolution of the patients’ motor performance both in single-session and longitudinal studies. Synergy-based assessments are subject to various sources of variability: natural trial-by-trial variability of performed movements, intrinsic characteristics of subjects that change over time (e.g., recovery, adaptation, exercise, etc.), as well as experimental factors such as different electrode positioning. These sources of variability need to be quantified in order to resolve challenges for the application of muscle synergies in clinical environments. The objective of this study is to analyze the stability and similarity of extracted muscle synergies under the effect of factors that may induce variability, including inter- and intra-session variability within subjects and inter-subject variability differentiation. The analysis was performed using the comprehensive, publicly available hand grasp NinaPro Database, featuring surface electromyography (EMG) measures from two EMG electrode bracelets. Methods. Intra-session, inter-session, and inter-subject synergy stability was analyzed using the following measures: variance accounted for (VAF) and number of synergies (NoS) as measures of reconstruction stability quality and cosine similarity for comparison of spatial composition of extracted synergies. Moreover, an approach based on virtual electrode repositioning was applied to shed light on the influence of electrode position on inter-session synergy similarity. Results. Inter-session synergy similarity was significantly lower with respect to intra-session similarity, both considering coefficient of variation of VAF (approximately 0.2–15% for inter vs. approximately 0.1% to 2.5% for intra, depending on NoS) and coefficient of variation of NoS (approximately 6.5–14.5% for inter vs. approximately 3–3.5% for intra, depending on VAF) as well as synergy similarity (approximately 74–77% for inter vs. approximately 88–94% for intra, depending on the selected VAF). Virtual electrode repositioning revealed that a slightly different electrode position can lower similarity of synergies from the same session and can increase similarity between sessions. Finally, the similarity of inter-subject synergies has no significant difference from the similarity of inter-session synergies (both on average approximately 84–90% depending on selected VAF). Conclusion. Synergy similarity was lower in inter-session conditions with respect to intra-session. This finding should be considered when interpreting results from multi-session assessments. Lastly, electrode positioning might play an important role in the lower similarity of synergies over different sessions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Variability of Muscle Synergies in Hand Grasps: Analysis of Intra- and Inter-Session Data

Pale

Atzori

Müller

et al. 2020

Sensors

View full text Add to dashboard Cite

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“…The BP protocol evaluated in the current study is an exercise that involves upper joints and muscles used in shot put. During the bench press exercise, horizontal adduction and elbow extension movements are performed, with activation of the pectoralis major, deltoid and triceps brachii muscles 24,25 . During the final phase of the shot put, the implement is vigorously pushed up and forward, in which subjects performed shoulder horizontal adduction and elbow extension 26 .…”

Section: Discussionmentioning

confidence: 99%

Bench press exercise performed as conditioning activity improves shot put performance in untrained subjects

Borba

Júnior

Ramos

et al. 2018

Motriz: rev. educ. fis.

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The aim of the present study was to evaluate the effect of bench press exercise performed as conditioning activity on the shot put performance in untrained subjects. Methods: Twelve healthy men (26 ± 6 years; 1.8 ± 0.1 m; 73.5 ± 10.4 kg; 13.2 ± 5.2% body fat), with no experience in shot put, were randomly assigned into two conditions: 1) Control: subjects performed six shot put attempts, and 2) Bench press exercise: subjects performed six shot put attempts 7 min post 2 sets of 5 repetitions maximum (RM) of bench press exercise. A metal ball of 4 kg was used for shot put attempts, and subjects were instructed to perform each shot put according to the static shot put technique. Results: Shot put performance was greater after bench press condition when compared with control condition (8.2 ± 1.2 m vs. 7.8 ± 0.8 m, respectively, p < 0.05). In addition, eight out of 12 volunteers positively responded to the conditioning activity. Conclusion: The results suggest that bench press exercise performed as a conditioning activity improves shot put performance in untrained subjects. Moreover, the conditioning activity should be individually set.

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“…In the recent literature, dimensionality reduction techniques have been widely used to quantify muscle coordination and to detect changes in muscle coordination following a natural or experimental event or procedure, including in pathological conditions (e.g., stroke [ 4 – 16 ]), cerebral palsy [ 17 – 19 ], Parkinson's disease [ 20 , 21 ], spinal cord injury [ 22 – 24 ], pain [ 25 – 27 ], or practicing sports [ 28 – 33 ]). These techniques represent complicated, high-dimensional muscle activations using a small number of motor modules, effectively reducing muscle activation dimensionality.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Selective Muscle Weakness on Muscle Coordination in the Human Arm

Roh

Beer

Lai

et al. 2018

Applied Bionics and Biomechanics

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Despite the fundamental importance of muscle coordination in daily life, it is currently unclear how muscle coordination adapts when the musculoskeletal system is perturbed. In this study, we quantified the impact of selective muscle weakness on several metrics of muscle coordination. Seven healthy subjects performed 2D and 3D isometric force target matches, while electromyographic (EMG) signals were recorded from 13 elbow and shoulder muscles. Subsequently, muscle weakness was induced by a motor point block of brachialis muscle. Postblock subjects repeated the force generation tasks. We quantified muscle coordination pre- and postblock using three metrics: tuning curve preferred direction, tuning curve area, and motor modules analysis via nonnegative matrix factorization. For most muscles, the tuning direction for the 2D protocol was not substantially altered postblock, while tuning areas changed more drastically. Typically, five motor modules were identified from the 3D task, and four motor modules were identified in the 2D task; this result held across both pre- and postblock conditions. The composition of one or two motor modules, ones that involved mainly the activation of shoulder muscles, was altered postblock. Our results demonstrate that selective muscle weakness can induce nonintuitive alternations in muscle coordination in the mechanically redundant human arm.

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Muscle synergies during bench press are reliable across days

Cited by 27 publications

References 34 publications

Variability of Muscle Synergies in Hand Grasps: Analysis of Intra- and Inter-Session Data

Variability of Muscle Synergies in Hand Grasps: Analysis of Intra- and Inter-Session Data

Bench press exercise performed as conditioning activity improves shot put performance in untrained subjects

The Effects of Selective Muscle Weakness on Muscle Coordination in the Human Arm

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