Use of unstable surfaces and conscious abdominal contraction on the activity of periscapular muscles

Abstract

Background/aims Core training has been recommended in shoulder rehabilitation programs. However, the evidence on this topic is still scarce. The aim of this study was to investigate the effect of conscious abdominal contraction combined with unstable surfaces on electromyographic activity of periscapular muscles during the plus phase of a push-up. Methods A total of 20 male participants (22.8 ± 2.5 years) were evaluated. Electromyographic signals were collected from the upper, middle and lower trapezius, serratus anterior, and external and internal oblique muscles during push-up exercises on a stable and unstable surface with and without the conscious abdominal contraction. Each participant performed four variations of the plus phase of a push-up. Results The results demonstrated that the conscious abdominal contraction caused an increase in the electromyographic activity of external oblique, internal oblique, serratus anterior and lower trapezius muscles (P≤0.008). The unstable surface caused only a relevant increase in electromyographic activity of the abdominal muscles (P≤0.025). Combining the two strategies did not increase the electromyographic activity of any muscles (P≥0.238). Conclusions The conscious abdominal contraction seems to be a viable strategy to increase the electromyographic activity of the periscapular muscles.

Electromyography of scapular stabilizers in people without scapular dyskinesis during push-ups: a systematic review and meta-analysis

“…Out of the 2,850 records identified in the primary search, 92 full text articles were reviewed in detail to check the eligibility. Thirty-eight studies met the inclusion criteria ( Figure 1 ) and were included in the qualitative analysis ( Lear and Gross, 1998 ; Lehman et al, 2008 ; Sandhu et al, 2008 ; Tucker et al, 2008 ; Maenhout et al, 2010 ; Park and Yoo, 2011 ; Tucker et al, 2011 ; Kim et al, 2012 ; Park et al, 2013a ; Park et al, 2013b ; Park et al, 2013c ; Lee et al, 2013 ; Seo et al, 2013 ; Yoo, 2013 ; Yoon and Lee, 2013 ; Calatayud et al, 2014a ; Calatayud et al, 2014b ; Calatayud et al, 2014c ; De Mey et al, 2014 ; Kim et al, 2014 ; McGill et al, 2014 ; Borreani et al, 2015a ; Borreani et al, 2015b ; Herrington et al, 2015 ; Lee et al, 2015 ; Gioftsos et al, 2016 ; Kim et al, 2016 ; Harris et al, 2017 ; Horsak et al, 2017 ; Torres et al, 2017 ; de Araújo et al, 2018 ; Kim and Yoo, 2019 ; de Araújo et al, 2020 ; Ferreira et al, 2020 ; Youdas et al, 2020 ; De Faria et al, 2021 ; Patselas et al, 2021 ; Ratanapinunchai and Madeeyoh, 2022 ). For the quantitative analysis, 7 studies had to be excluded ( Lear and Gross, 1998 ; Kim et al, 2012 ; Lee et al, 2013 ; Yoo, 2013 ; Yoon and Lee, 2013 ; Borreani et al, 2015b ; Kim et al, 2016 ).…”

“…Two of the 38 included studies included two groups (control and scapular dyskinesis) ( de Araújo et al, 2018 ; De Faria et al, 2021 ) , and the other 36 included only healthy subjects. Twenty-eight out of 38 selected studies were conducted with male subjects ( Lehman et al, 2008 ; Sandhu et al, 2008 ; Park and Yoo, 2011 ; Park et al, 2013a ; Park et al, 2013b ; Park et al, 2013c ; Lee et al, 2013 ; Seo et al, 2013 ; Yoo, 2013 ; Yoon and Lee, 2013 ; Calatayud et al, 2014a ; Calatayud et al, 2014b ; Calatayud et al, 2014c ; Kim et al, 2014 ; McGill et al, 2014 ; Borreani et al, 2015a ; Borreani et al, 2015b ; Lee et al, 2015 ; Gioftsos et al, 2016 ; Kim et al, 2016 ; Torres et al, 2017 ; de Araújo et al, 2018 ; Kim and Yoo, 2019 ; de Araújo et al, 2020 ; Ferreira et al, 2020 ; De Faria et al, 2021 ; Patselas et al, 2021 ; Ratanapinunchai and Madeeyoh, 2022 ), 8 studies were conducted with mixed samples ( Lear and Gross, 1998 ; Tucker et al, 2008 ; Maenhout et al, 2010 ; Tucker et al, 2011 ; De Mey et al, 2014 ; Herrington et al, 2015 ; Harris et al, 2017 ; Youdas et al, 2020 ), and one study was conducted with female subjects ( Horsak et al, 2017 ). Gender was not reported in one study ( Kim et al, 2012 ).…”

“…In addition, various unstable tools, such as oscillating unstable surface, balance board, wobble board, proprioceptive board, balance cushion, balance pads, Airex pad, fitness dome, balance discs, sling, training balls (Bosu ball, Swiss ball, Gym ball, rubber ball, dynamic cushion ball), inflated platforms, foam mat, cuff link, and mini trampoline were used during exercises. According to EMG analysis, the normalization process was performed based on the maximum voluntary isometric contraction (MVIC) (27 studies) ( Lear and Gross, 1998 ; Sandhu et al, 2008 ; Tucker et al, 2008 ; Maenhout et al, 2010 ; Tucker et al, 2011 ; Lee et al, 2013 ; Seo et al, 2013 ; Yoo, 2013 ; Yoon and Lee, 2013 ; Calatayud et al, 2014a ; Calatayud et al, 2014b ; Calatayud et al, 2014c ; De Mey et al, 2014 ; Borreani et al, 2015a ; Borreani et al, 2015b ; Herrington et al, 2015 ; Lee et al, 2015 ; Gioftsos et al, 2016 ; Kim et al, 2016 ; Horsak et al, 2017 ; de Araújo et al, 2018 ; de Araújo et al, 2020 ; Ferreira et al, 2020 ; Youdas et al, 2020 ; De Faria et al, 2021 ; Patselas et al, 2021 ; Ratanapinunchai and Madeeyoh, 2022 ), the maximal voluntary contraction (MVC) (7 studies) ( Lehman et al, 2008 ; Park et al, 2013a ; Park et al, 2013b ; Park et al, 2013c ; Kim et al, 2014 ; McGill et al, 2014 ; Kim and Yoo, 2019 ), the reference voluntary isometric contraction (RVIC) (1 study) ( Torres et al, 2017 ), the reference voluntary contraction (RVC) (2 studies) ( Park and Yoo, 2011 ; Kim et al, 2012 ) and the reference isometric contraction (RIC) (1 study) ( Harris et al, 2017 ).…”

“…However, due to the observational nature of EMG activity analysis, it was not possible to blind the examiners. Since only 7 studies ( Seo et al, 2013 ; Kim et al, 2014 ; de Araújo et al, 2018 ; de Araújo et al, 2020 ; Ferreira et al, 2020 ; Youdas et al, 2020 ; De Faria et al, 2021 ) included a physical examination by one or two clinical experts to evaluate scapular dyskinesis or ensure normal scapulohumeral rhythm and verify the upper limb structures, internal validity in other studies may have been compromised. Six studies ( Park et al, 2013a ; Yoo, 2013 ; Yoon and Lee, 2013 ; Herrington et al, 2015 ; de Araújo et al, 2020 ; Ferreira et al, 2020 ) did not randomize the order of exercises, which increases the risk of selection bias related to potential fatigue.…”

Role of kinetic chain in sports performance and injury risk: a narrative review

“…Electromyography studies have demonstrated that ipsilateral lower-limb extension amplifies the activation of the serratus anterior, whereas contralateral lower-limb extension reduces its activation [ 52 ]. Consciously contracting the abdominal muscles was an effective strategy to magnify the serratus anterior and lower trapezius activity (as proven by the electromyographical readings) during the push-up plus phase [ 53 ].…”