Scapular Muscle Activity During Static Yoga Postures

The effects of shoulder stabilization exercises on muscle strength, proprioceptive sensory ability and performance in office workers with shoulder protraction

Objectives. Shoulder protraction is frequently seen in office workers because of working with excessive trunk flexion for a long time. This study aimed to compare the effectiveness of stabilization exercises (SE) given in addition to office exercises (OE). Methods. Sixty office workers with shoulder protraction were divided into SE + OE (n = 30) and OE (n = 30) groups by stratified random sampling for 8 weeks and followed up for 4 weeks. Shoulder protraction was assessed with a caliper, muscle strength with a hand-held dynamometer, proprioception with an isokinetic dynamometer, vibration sense with a vibrometer and upper extremity functional performance with the closed kinetic chain upper extremity stability test. Results. There were significant improvements in all parameters in the OE + SE group, while increases in the strength of the upper trapezius, pectoralis major and infraspinatus muscles and in upper extremity functional performance were also found in the OE group (p < 0.05). During detraining, shoulder protraction, muscle strength, proprioception and upper extremity performance showed longer-term improvement with SE + OE (p < 0.05). Conclusion. The results obtained with the exercises demonstrate the importance of SE + OE in terms of maintaining proper posture and improving shoulder proprioception, muscle strength and functional performance.

The Role of Objective Movement Analysis in the Control of Yoga Asanas: A Case Study

INTRODUCTION

Yoga is classified as a form of complementary and alternative medicine. It can be used in many disciplines including physiotherapy, medicine, and sport. The objective of the study was to identify possible biomechanical problems during yoga practice and to minimize the risk of injury.

CASE PRESENTATION

Objective evaluation of the symmetry of asanas, balance, stability, and muscle tension was provided in case of a 37-year-old woman, practicing mainly aerial and Hatha yoga for 6 years. The bigger body tilt and deviations in center of pressure (COP) parameters were observed in tadasana during forward examinations. In tadasana, the highest muscle activity was observed in the rectus femoris. In case of forward tadasana observation, the highest activity was found in the gastrocnemius and in the lumbar portion of the erector spinae. During backward tadasana trial, the most active were the tibialis anterior and rectus femoris muscles. In garudasana and natarajasana, the symmetry of the trunk position in relation to the lower limbs was observed, regardless of the supporting limb. In the same way, COP parameters in garudasana were similar regardless of the supporting limb. However, in natarajasana, the higher COP displacement parameters were observed in the case of the nondominant supporting limb. As for the electromyographic evaluation of garudasana and natarajasana, the highest muscle activity was observed in the lumbar portion of the erector spinae. In chakrasana, a slightly greater angle of the hip extension was observed in the left hip. A higher muscle activity in chakrasana was observed in the lumbar portion of the right erector spinae. In sirsasana, no significant displacements of the cervical spine were observed, but a higher activity of the left sternocleidomastoid muscle was found.

CONCLUSION

With the use of objective movement analysis, possible biomechanical problems were identified. Attention should be paid to the normalization of the tension in the lumbar part of the right erector spinae and the right sternocleidomastoid muscle, as well as to the balance training in positions on the nondominant lower limb. Objective movement analysis can be a useful tool for instructors or physiotherapists to adjust yoga programs and correct asanas in order to avoid future injuries.

Einleitung

Yoga gilt als Form der Komplementär- und Alternativmedizin. Es ist in vielen Disziplinen einsetzbar, von Physiotherapie über Medizin bis Sport. Das Ziel dieser Studie war es, mögliche biomechanische Probleme bei der Ausübung von Yoga zu identifizieren, um das Verletzungsrisiko zu minimieren.

Vorstellung des Falls

Eine objektive Beurteilung der Symmetrie der Asanas, des Gleichgewichts, der Stabilität und der Muskelspannung erfolgte bei einer 37-jährigen Frau, die seit 6 Jahren hauptsächlich Aerial- und Hatha-Yoga praktiziert. Stärkere Körperneigung und Abweichungen bei Druckmittelpunkt-Parametern wurden in Tadasana bei der Vorwärts-Beobachtung festgestellt. In Tadasana wurde die höchste Muskelaktivität im Rectus femoris beobachtet. Bei der Tadasana-Vorwärts-Beobachtung war die höchste Aktivität im Gastrocnemius und im lumbalen Anteil des Erector spinae zu verzeichnen. Während der Tadasana-Rückwärts-Übung waren die aktivsten Muskeln der Tibialis anterior und Rectus femoris. In Garudasana und Natarajasana wurde die Symmetrie der Rumpfposition im Verhältnis zu den unteren Gliedmaßen unabhängig von der belasteten Gliedmaße beobachtet. Ebenso waren die Parameter des Druckmittelpunkts (DMP) in Garudasana unabhängig von der belasteten Gliedmaße vergleichbar. In Natarajasana wurden jedoch höhere Parameter der DMP-Verschiebung bei der nicht-dominanten belasteten Gliedmaße beobachtet. Bei der elektromyografischen Auswertung von Garudasana und Natarajasana wurde die höchste Muskelaktivität im lumbalen Anteil des Erector spinae beobachtet. In Chakrasana wurde ein etwas größerer Winkel der Hüftstreckung im linken Hüftgelenk beobachtet. Eine höhere Muskelaktivität in Chakrasana wurde im lumbalen Anteil des rechten Erector spinae beobachtet. In Sirsasana wurden keine signifikanten Verschiebungen der Halswirbelsäule beobachtet, jedoch war eine höhere Aktivität des linken Sternocleidomastoideus zu verzeichnen.

Schlussfolgerung

Mit Hilfe einer objektiven Bewegungsanalyse wurden mögliche biomechanische Probleme identifiziert. Mit besonderer Aufmerksamkeit sollte auf die Normalisierung der Spannung im lumbalen Anteil des rechten Erector spinae und des rechten Sternocleidomastoideus sowie auf die Schulung des Gleichgewichts in Positionen auf der nicht-dominanten unteren Extremität geachtet werden. Die objektive Bewegungsanalyse kann ein nützliches Instrument für Instruktoren oder Physiotherapeuten sein, um Yoga-Programme anzupassen und Asanas zu korrigieren, um Verletzungen vorzubeugen.

Reducing Stress with Yoga: A Systematic Review Based on Multimodal Biosignals

Stress is an enormous concern in our culture because it is the root cause of many health issues. Yoga asanas and mindfulness-based practices are becoming increasingly popular for stress management; nevertheless, the biological effect of these practices on stress reactivity is still a research domain. The purpose of this review is to emphasize various biosignals that reflect stress reduction through various yoga-based practices. A comprehensive synthesis of numerous prior investigations in the existing literature was conducted. These investigations undertook a thorough examination of numerous biosignals. Various features are extracted from these signals, which are further explored to reflect the effectiveness of yoga practice in stress reduction. The multifaceted character of stress and the extensive research undertaken in this field indicate that the proposed approach would rely on multiple modalities. The notable growth of the body of literature pertaining to prospective yoga processes is deserving of attention; nonetheless, there exists a scarcity of research undertaken on these mechanisms. Hence, it is recommended that future studies adopt more stringent yoga methods and ensure the incorporation of suitable participant cohorts.

Scapular kinematics and muscle activity during Yi Jin Bang exercises

Introduction: Scapular dyskinesis is commonly associated with subacromial pain syndrome (SAPS). Addressing scapular dyskinesis is widely accepted as an important component of shoulder rehabilitation. Our previous randomized controlled trial showed that Yi Jin Bang (YJB) exercises could effectively manage SAPS, but scapular motions and muscle activity during YJB exercises remain unknown. This study examined scapular kinematics synchronously with scapular muscle activation during YJB exercises. Methods: Thirty healthy participants with no shoulder complaints were enrolled in this study. Three-dimensional (3D) scapular kinematics and electromyography (EMG) activation of the upper trapezius, middle trapezius, lower trapezius, serratus anterior, anterior deltoid, middle deltoid, and posterior deltoid were synchronously measured during nine YJB movements. Results: During all YJB movements, the scapula was upwardly rotated and anteriorly tilted, with more upward rotation and a similar or less anterior tilt than the mean resting scapular angle. Column rotation, arm crossover, shoulder support circle, and armpit support high lift generated more internal rotation than the mean resting scapular angle, with the angles of internal rotation significantly greater than the other five movements (p < 0.001). Regarding EMG activity, all YJB movements elicited low activity (1.42%-19.19% maximal voluntary isometric contraction [MVIC]) from the upper trapezius and posterior deltoid and low to moderate activity (0.52%-29.50% MVIC) from the middle trapezius, lower trapezius, serratus anterior, anterior deltoid, and middle deltoid. Conclusion: YJB exercises could be useful in the middle to later phases of shoulder rehabilitation. For patients with insufficient external rotation, some YJB movements should be prescribed with caution.

The relative activation of pelvic floor muscles during selected yoga poses

BACKGROUND

Individuals with pelvic floor muscle (PFM) dysfunction can benefit from core stabilization exercises. Yoga is a popular activity that can generate moderate to high trunk activity and has been shown to benefit this patient population. No data exist regarding PFM activity during yoga. Determining PFM activity will provide important information for developing an evidence-based exercise program.

OBJECTIVES

To determine the relative activation of the PFM during select yoga poses.

STUDY DESIGN

Cross-sectional design.

METHODS

Perianal surface EMG sensors were used to capture levator ani (LA) activation. Peak activity of a maximum voluntary isometric contraction (MVIC) represented 100% activity. For testing, subjects held the following poses for 30 s: locust; modified side plank; side angle; and hands-clasped front plank. The average EMG activity, expressed as a 100% percent of the MVIC (%MVIC), from 5 to 25 s of each pose was analyzed.

RESULTS

Subjects generated the most activity (63.5 %MVIC) during the locust. Side angle (35.3 %MVIC) required greater activity than the side (29.1 %MVIC) and front planks (26.3 %MVIC). Locust activity was significantly greater (P < 0.001) than all poses; side angle activity was significantly greater (P < 0.01) than the front and side planks.

CONCLUSION

LA activation during locust was very high and sufficient for strength gains. LA activation during side angle, front plank, and side plank would be best for improving endurance and/or neuromuscular control of the PFM. Findings from this study showed differing levels of PFM activation across yoga poses that may benefit patients with pathology associated with PFM dysfunction.

Influence of scapular motion cues on trapezius muscle activity during Y exercise

BACKGROUND

The Y exercise is a therapeutic exercise facilitating lower trapezius muscle activity.

OBJECTIVE

To identify the effects of scapular movement cues (posterior tilt vs. posterior tilt with adduction/depression) on trapezius muscle activity during Y exercise.

METHODS

Fifteen healthy men without current shoulder pain performed general Y exercise; Y exercise with cues for scapular posterior tilt; and Y exercise with cues for scapular posterior tilt, adduction, and depression. Electromyography (EMG) data for the trapezius muscles were collected during Y exercise. The posterior tilt angle of the scapula was measured in the prone position with and without cues for scapular posterior tilt using an inclinometer application.

RESULTS

The greatest lower trapezius muscle activity was observed during Y exercise with cues for scapular posterior tilt, while the greatest EMG activity of the upper trapezius was observed during Y exercise with cues for scapular posterior tilt, adduction, and depression (p< 0.05). Middle trapezius muscle activity did not significantly differ among the three Y exercise conditions (p= 0.175). Cues for scapular posterior tilt significantly increased the scapular posterior tilt angle in the prone shoulder abduction position (p= 0.007).

CONCLUSION

Cues for scapular posterior tilt were most effective in facilitating lower trapezius muscle activity during Y exercise.

Interrater Reliability of an Observational Rating Scale and Video Analysis of Yoga Poses

CONTEXT

Yoga is increasingly popular, not only as a form of recreational exercise but also as a physician-recommended intervention for health conditions. While serious adverse effects accompanying yoga practice are rare, poses that involve upper-extremity weight-bearing have a high risk of discomfort. To better understand factors contributing to adverse effects, there is a critical need for robust instruments that objectively evaluate pose performance. The purpose of this study was to assess the interrater reliability of an observational scale developed to assess the alignment of 3 yoga poses.

DESIGN

Cross-sectional experimental study.

METHODS

Thirty-eight individuals were given standardized instructions and performed 3 poses (Downward Dog, Plank, and Side Plank). Lateral videos were rated by 2 raters. A rating scale evaluating the alignment of 7 regions was developed by the study team with input from yoga teachers. Descriptive statistics were used to summarize the percentage of subjects showing ideal alignment and deviations. Interrater reliability was quantified using Cohen kappa coefficient (κ).

RESULTS

In Downward Dog, the prevalence of ideal alignment was 20%, 28%, and 37%, at the neck, shoulder, and back, respectively; κ ranged from .44 to .69. In Plank, the prevalence of ideal alignment was 31%, 45%, and 54% at the neck, shoulder, and back, respectively; κ ranged from .47 to .95. In Side Plank, the prevalence of ideal alignment was 16, 41%, and 24%, at the neck, shoulder, and back, respectively; κ ranged from .20 to .84.

CONCLUSION

The observational scale found a high prevalence of deviations, and demonstrated fair to substantial interrater agreement.

Effects of Intended Scapular Posterior Tilt Motion on Trapezius Muscle Electromyography Activity

The intended scapular motion is a strategy to strengthen the lower trapezius (LT). However, few studies have explored the effects of the intended scapular posterior tilt motion on selective LT activation. Thus, the present study investigated the effect of the intended scapular posterior tilt on the electromyography (EMG) activity of trapezius muscles during prone shoulder horizontal abduction (PSHA). Eighteen asymptomatic men performed three types of PSHA: (1) preferred PSHA, (2) PSHA with the intended scapular posterior tilt, and (3) PSHA with the intended scapular posterior tilt and trunk extension. EMG activity of the upper trapezius (UT), middle trapezius (MT), and LT were measured during PSHAs. Scapular posterior tilt angle, with and without the intended scapular posterior tilt, were measured using inclinometer. The results indicated that LT muscle activity increased when scapular posterior tilt was applied with and without trunk extension (14-16%), compared to the preferred condition, during PSHA (p < 0.05). However, the addition of trunk extension to PSHA with the intended scapular posterior tilt increased the UT muscle activity (28%) and the UT/LT (29%) and UT/MT (31%) ratios (p < 0.05). The scapular posterior tilt angle was higher (15%) when applying the intended scapular posterior tilt (p = 0.020). These findings suggest that the intended scapular posterior tilt may be a useful strategy for selective LT muscle activation.

Dynamic evaluation of the contractile function of lumbodorsal muscles during locust pose in yoga by real-time ultrasound

Background and Purpose

Chronic low back pain (CLBP), which has a close relationship with lumbar muscle degeneration, can be effectively treated by exercise therapy, and yoga has been widely accepted by clinicians and patients with CLBP. The purpose of this study was to observe the changes in the thickness of lumbodorsal muscles that occur during locust pose in yoga and how these changes occur. From the changes in muscle thickness that occur in the locust pose, the contractile function of lumbodorsal muscles can be evaluated.

Methods

Fifty-two healthy volunteers (from May 2019 to August 2019, age from 28 to 68 years, 23 males and 29 females (age: 40 ± 8 years; weight: 68.3 ± 5.2 kg; height: 170.2 ± 13.1 cm) were recruited, and lumbodorsal muscle, including the multifidus, longissimus, iliocostalis, and quadratus lumborum, ultrasonic examinations were carried out in the relaxed and contracted states. The changes in the thickness of the lumbodorsal muscles in the relaxed and contracted states were dynamically observed by real-time ultrasound when subjects were performing the locust yoga pose. Then, the thicknesses of the muscles during the two states were measured to calculate the ratio of contraction of each muscle and determine the statistical significance of the change in thickness of each muscle.

Results

The mean thickness of the left multifidus in the relaxed state was 1.32 ± 0.27 cm (95 % CI: 1.24 ~ 1.39), that in the contracted state was 1.60 ± 0.30 cm (95 % CI: 1.52 ~ 1.69) (obviously different between the relaxed and contracted states, P < 0.001), and those in the corresponding right side were 1.37 ± 0.31 cm (95 % CI: 1.29 ~ 2.46) and 1.68 ± 0.38 cm (95 % CI: 1.58 ~ 1.79) (P < 0.001), respectively. The mean thickness of the left quadratus lumborum in the relaxed state was 1.38 ± 0.32 cm (95 % CI: 1.29 ~ 1.47), that in the contracted state was 1.62 ± 0.40 cm (95 % CI: 1.50 ~ 1.73) (P = 0.001), and those in the corresponding right side were 1.30 ± 0.32 cm (95 % CI: 1.21 ~ 1.39) and 1.55 ± 0.41 cm (95 % CI: 1.44 ~ 1.67) (P = 0.001), respectively. The mean thickness of the left longissimus in the relaxed was 2.33 ± 0.51 cm (95 % CI: 2.19 ~ 2.47), that in the contracted state was 3.20 ± 0.61 cm (95 % CI: 3.03 ~ 3.37) (P < 0.001), and those in the corresponding right side were 2.34 ± 0.49 cm (95 % CI 2.20 ~ 2.48) and 3.26 ± 0.68 cm (95 % CI 3.07 ~ 3.45) (P < 0.001), respectively. The mean thickness of the left iliocostalis in the relaxed state was 1.88 ± 0.41 cm (95 % CI: 1.76 ~ 1.99), that in the contracted state was 2.34 ± 0.49 cm (95 % CI: 2.00 ~ 2.47) (P < 0.001), and those in the corresponding right side were 1.98 ± 0.40 cm (95 % CI: 1.87 ~ 2.09) and 2.44 ± 0.56 cm (95 % CI: 2.29 ~ 2.60) (P < 0.001), respectively. The mean contracted state/resting state (C/R) of the longissimus was 1.39 ± 0.14 on the left and 1.40 ± 0.16 on the right. The multifidus and iliocostalis had the second highest C/R. The mean C/R of the multifidus was 1.23 ± 0.12 on the left and 1.24 ± 0.15 on the right, and the mean C/R of the iliocostalis was 1.25 ± 0.12 on the left and 1.24 ± 0.14 on the right. The quadratus lumborum had the lowest C/R, and the mean C/R of the quadratus lumborum was 1.17 ± 0.10 on the left and 1.19 ± 0.11 on the right.

Conclusions

Ultrasound can be used to dynamically assess the contractile function of the lumbar muscle in the locust pose of yoga, the C/R ratio can be used to indicate the ability of a muscle to contract, and dynamic ultrasound can guide lumbar exercise and feedback the exercise results. The establishment of this model allowed data regarding the contraction state of the lumbar muscle to be obtained in a normal population, and based on this, future studies can further explore and evaluate the contraction state of the lumbar muscle after yoga exercise in CLBP patients, the effect exercise on lumbar instability and on a patient population after lumbar operation.

Functional status in adhesive capsulitis - yoga vs. physiotherapy: a quasi experimental study

OBJECTIVES

Adhesive capsulitis results in a multidimensional disability which demands a polygonal approach. Although physiotherapy proves an essential for a complete and comprehensive recovery in adhesive capsulitis, evidence also suggest the role of yoga in the management, hence this study investigate their effectiveness.

METHODS

This is a quasi-randomised control study. A pre-diagnosed subacute and chronic adhesive capsulitis of shoulder, between the age group of 35-60 years of both genders of total 40 participants were randomly divided into Group 'A' (yogasana) and Group 'B' (physiotherapy). The parameters of pain, joint mobility and functional disabilities were measured at the baseline and after four-weeks.

RESULTS

The mean age of Group 'A' was 45.4 ± 7.78 years whereas 50.05 ± 5.98 years was in Group 'B'. Intragroup analysis for both the groups showed statistically significant improvement in all the study variables. Whereas in intergroup analysis yogasana was found to be statistically significant in improving shoulder abduction mobility, p=0.03, effect size r=0.35 and also in shoulder flexion (p=0.15, r=0.23) and shoulder internal rotation (p=0.07, r=0.3), though statistically not significant, in view of small effect size response.

CONCLUSIONS

Both techniques improved the functional status in adhesive capsulitis, however additional effects on joint mobility was demonstrated by yogasana.

The Relationship Between Surface Electromyographic Activity and Torque Production of the Infraspinatus Muscle in Shoulder Rehabilitation Exercises

In current rehabilitation practice, exercise selection is commonly based on the amount of muscle recruitment demonstrated by electromyographic (EMG) analysis. A preponderance of evidence supports the concept that EMG of a muscle and torque output are positively correlated. This study was designed to investigate the relationship between surface EMG activity of the infraspinatus and torque production during exercises involving shoulder external rotation (ER). A total of 30 participants (average age = 24.6 y) performed maximum voluntary isometric contraction of ER at 5 points within the range of motion of 3 shoulder exercise positions with concomitant surface EMG recording. As a maximal internally rotated position was approached, maximum ER torque and minimum or near-minimum EMG recruitment were demonstrated. Conversely, at maximally externally rotated positions, EMG activity was greatest and torque values were lowest. An inverse relationship between joint torque output and EMG activity was established in each of the 3 exercises. The inverse relationship between EMG activity and torque output during Shoulder ER suggests that there may be additional factors warranting consideration during exercise selection. Further research may be needed to determine the relative value of electrical activity versus torque output to optimize the selection of rehabilitative exercises.