The aim of this study was to evaluate the acute effect of the use of stable and unstable surfaces on electromyography (EMG) activity and coactivation of the scapular and upper-limb muscles during the push-up plus (with full protraction of the scapula). Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major, biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) levels and coactivation index were determined by surface EMG in 20 young men during push-up plus performed on a stable and unstable condition (2 unstable devices applied to hands and feet). The paired t test and Cohen d were used for statistical analysis. The results showed that during the execution of the push-up plus on the unstable surface an increased EMG activity of the scapular stabilizing muscles (SA, MT, and LT) was observed, while AD and PD muscles showed a decrease. During exercise execution on the unstable surface there was a higher index of coactivation of the scapular muscles (SA–MT and UT–LT pairs). No significant differences were observed in TB–BB and AD–PD pairs. These results suggest that the push-up-plus exercise associated with unstable surfaces produced greater EMG activity levels and coactivation index of the scapular stabilizing muscle. On the other hand, the use of an unstable surface does not promote the same effect for the shoulder muscles.
Search Results
Shoulder Muscle Activation Levels During the Push-Up-Plus Exercise on Stable and Unstable Surfaces
Rafaela J.B. Torres, André L.T. Pirauá, Vinícius Y.S. Nascimento, Priscila S. dos Santos, Natália B. Beltrão, Valéria M.A. de Oliveira, Ana Carolina R. Pitangui, and Rodrigo C. de Araújo
The Effect of Ankle Bracing and Taping on Joint Position Sense in the Stable Ankle
Eric J. Heit, Scott M. Lephart, and Susan L. Rozzi
The purpose of this study was to determine the proprioceptive effects of ankle bracing and taping. Proprioception was assessed in 26 subjects by evaluating ankle joint position sense, which was determined by the subjects' ability to actively reproduce a passively positioned joint angle. Testing was performed at positions of 30° of plantar flexion and 15° of inversion. Each subject underwent four trials at each test angle under three conditions: braced, taped, and control. For the plantar flexion test, both the braced condition and the taped condition significantly enhanced joint position sense when compared to the control condition. There was no significant difference between the braced and taped conditions. For the inversion test, the taped condition significantly enhanced joint position sense compared to the control condition. There was no significant difference between the braced and the control conditions or between the braced and the taped conditions. This study demonstrates that ankle bracing and taping improve joint position sense in the stable ankle.
Shoulder Muscle Activation Levels During Exercises With Axial and Rotational Load on Stable and Unstable Surfaces
Vinícius Yan Santos Nascimento, Rafaela Joyce Barbosa Torres, Natália Barros Beltrão, Priscila Soares dos Santos, André Luiz Torres Pirauá, Valéria Mayaly Alves de Oliveira, Ana Carolina Rodarti Pitangui, and Rodrigo Cappato de Araújo
This study evaluated the effects of instability on the EMG activity of scapular stabilizing and upper limb muscles during exercises with axial and rotational load. Twenty male volunteers (20.9 ± 1.8 years, 174.1 ± 0.04 cm, 73.17 ± 8.77 kg) experienced in strength training participated in a crossover design. Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major (PM), biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) were determined on both conditions. Participants performed a single series of 10 repetitions of bench press and fly exercises on stable (bench) and unstable (proprioceptive disc) conditions at 60% of 1-RM. The Friedman test and post hoc Dunn’s indicated that the unstable condition showed greater EMG activity for AD (P = .001) and BB (P = .002) on the fly exercise, SA (P = .001) and LT (P = .048) on the bench press, and PM (P ≤ .002) on both exercises. These results show that using an unstable surface in exercises with rotational load provides superior EMG activity of the agonist muscles, while in exercise with axial load, the instability favors EMG activity of the scapular stabilizing muscles.
Adaptive Regulation in a Stable Performance Environment: Trial-To-Trial Consistency in Cue Sports Performance
Jing Wen Pan, Pui Wah Kong, and John Komar
was that the adaptation effect would be less pronounced in low-skilled players. Their error correction would be more stable across the trials and not adapted to the error level (i.e., unable to modify regardless of small or large errors). Methods Participants This study was approved by the Nanyang
Stable or Fluid? An Investigation Into Female Student Athlete Basketball Players’ Well-Being
Allison Columbus, Diane E. Mack, Philip M. Wilson, and Nicole J. Chimera
) or four (e.g., Grimson et al., 2021 ) assessments has yielded no statistical differences in well-being, implying that this component of mental health is stable over time in athletes. By contrast, other research has noted evidence of person-level changes in well-being, leading researchers to contend
Effects of Trial Duration on Intrasession Reliability of Single Leg Balance Testing on Stable and Unstable Surfaces
Bryan L. Riemann, Kelsey Piersol, and George J. Davies
Context: Single leg balance testing is a commonly used tool in sports medicine; however, there has been no consensus on trial duration needed to obtain reliable measures. Objective: This investigation sought to determine the minimum trial duration required to obtain the highest intrasession single and average trial reliability for single leg balance testing on stable and unstable surfaces using dominant and nondominant limbs. Design: Intrasession reliability. Setting: Biomechanics laboratory. Participants: 70 healthy (35 men, 35 women), physically active young adults aged 22.8 ± 2.8 y divided into 3 subgroups (n = 10, 30, 30) across a 3-phase study. Methods: 3 phases of single leg balance testing were performed. For phase 1, the duration of time each participant could maintain posture on each limb/surface were computed. Phase 2 considered performance for 6 cumulative time intervals (5s, 10s, 15s, 20s, 25s, 30s). Phase 3 served to solidify results of phase 2 by computing reliability of 15s trials. Main outcome measures: Overall stability index of the center of pressure and platform tilt. Results: Intraclass correlation coefficients for phase 2 ranged from .74 (5s interval for nondominant limb on unstable surface) to .94 (20s interval for nondominant limb on stable surface). Phase 3 intraclass correlation coefficients ranged from .66 to .78 for single trial and .85 to .92 for 3 trial average with coefficients of variation ranging from 23.9% to 40.4% for single trial and 13.8% to 23.0% for 3 trial average. Conclusions: These results ultimately suggest 15s as the optimal trial duration to provide reliable measures while reducing compensatory event occurrence.
An Assessment of the Validity of the Remote Food Photography Method (Termed Snap-N-Send) in Experienced and Inexperienced Sport Nutritionists
Reuben G. Stables, Andreas M. Kasper, S. Andy Sparks, James P. Morton, and Graeme L. Close
methods of dietary assessment. Such estimates of validity should therefore be taken into account when utilizing this method, alongside the requirement to use multiple coders when performing a dietary analysis of athletic populations. Acknowledgments The study was designed by R.G. Stables, A.M. Kasper, J
Acquiring a Stable Estimate of Physical Activity in Adults With Visual Impairment
Elizabeth A. Holbrook, Minsoo Kang, and Don W. Morgan
As a first step toward the development of adapted physical activity (PA) programs for adults with visual impairment (VI), the purpose of this study was to determine the time frame needed to reliably estimate weekly PA in adults with VI. Thirty-three adults with VI completed 7 days of pedometer-based PA assessment. Generalizability theory analyses were conducted to quantify sources of variance within the PA estimate and determine the appropriate number of days of PA monitoring needed for the total sample and for participants with mild-to-moderate and severe VI. A single-facet, crossed design was employed including participants and days. Participants and days correspondingly accounted for 33–55% and 0–3% of the total variance in PA. While a reliable account of PA was obtained for the total sample over a 6-day period, shorter (4-day) and longer (9-day) periods were required for persons with mild-to-moderate and severe VI, respectively.
Long-Term Parallel Changes of Physical Activity and Body Mass Index in Different Predisposing Risk Trajectories of Obesity
Parisa Naseri, Parisa Amiri, Fatemeh Mahani, Amirali Zareie-Shabkhaneh, and Fereidoun Azizi
Using the cluster analysis, results in each examination the trajectory patterns of risk clusters were obtained, and similar patterns were categorized into 3 different classes named stable low-risk, unstable risk, and stable high-risk trajectory groups. Statistical Analysis Basic Characteristics Baseline
Changes in Posture Following a Single Session of Long-Duration Water Immersion
Stephen M. Glass, Christopher K. Rhea, Matthew W. Wittstein, Scott E. Ross, John P. Florian, and F.J. Haran
For balance testing, subjects were instructed to remain as motionless as possible during three 70-second trials of double-leg quiet stance in 4 conditions—eyes open/stable surface (Open-Stable), eyes open/foam surface (Open-Foam), eyes closed/stable surface (Closed-Stable), and eyes closed
