Electromyographic Activities of Trunk Muscles Due to Different Exercise Intensities during Pulley-based Shoulder Exercises on an Unstable Surface

[Purpose] This study examined the relationship between core stability and exercise intensity during a pulley-based shoulder exercise (PBSE) on an unstable support surface. [Subjects] Twenty healthy college students enrolled in this study. [Methods] Surface EMG was carried out in twenty healthy adult men. The electromyographic activities of the rectus abdominis (RA), erector spinae (ES), exercises with 14 kg or 26 kg of resistance and external oblique (EO) muscles during pulley-based shoulder on an unstable support surface (USS) were compared. [Results] The EMG signals of the RA, ES, and EO did not increase with increasing exercise resistance. [Conclusion] Increasing the exercise intensity to increase the core stability during PBSE on a USS may be ineffective.Key words: Electromyography, Core stability, Ankle strategy     

Characteristics of the scapula movement during shoulder elevation depend on posture

[Purpose] This study aimed to clarify the differences in scapular movement during flexion and abduction of the shoulder joint with different postures. [Participants and Methods] This study included 15 male participants. Their shoulder flexion and abduction and angles of the scapular upward rotation, scapular anterior tilt, scapular external rotation, and thoracic spine flexion were measured. Measurements were taken in three positions: the control, thoracic spine flexion, and thoracic spine extension positions using a three-dimensional motion capture system. [Results] In the shoulder flexion, the amount of change in the scapular external rotation was significantly greater in the thoracic flexion than in the thoracic extension. In shoulder abduction, the amount of change in the scapular anterior tilt and external rotation was significantly greater in the thoracic flexion than in the thoracic extension. A comparison of the scapular angles in shoulder flexion and abduction showed that the upward rotation, posterior tilt, and external rotation were significantly greater in abduction than flexion. [Conclusion] To avoid posture-induced incoordination of the scapula and thorax movement during shoulder elevation, postural adjustment of the thoracic spine based on the movements is necessary for the shoulder joint exercises.     

Rehabilitation Exercises to Induce Balanced Scapular Muscle Activity in an Anti-gravity Posture

[Purpose] The purpose of this study was to compare the intramuscular balance ratios of the upper trapezius muscle (UT) and the lower trapezius muscle (LT), and the intermuscular balance ratios of the UT and the serratus anterior muscle (SA) among prone extension (ProExt), prone horizontal abduction with external rotation (ProHAbd), forward flexion in the side-lying position (SideFlex), side-lying external rotation (SideEr), shoulder flexion with glenohumeral horizontal abduction load (FlexBand), and shoulder flexion with glenohumeral horizontal adduction load (FlexBall) in the standing posture. [Methods] The electromyographic (EMG) activities of the UT, LT and SA were measured during the tasks. The percentage of maximum voluntary isometric contraction (%MVIC) was calculated for each muscle, and the UT/LT ratios and the UT/SA ratios were compared among the tasks. [Results] The UT/LT ratio with the FlexBand was not significantly different from those of the four exercises in the side-lying and prone postures. The UT/SA ratio with the FlexBall demonstrated appropriate balanced activity. [Conclusion] In an anti-gravity posture, we recommend the FlexBand and the FlexBall for inducing balanced UT/LT and UT/SA ratios, respectively.Key words: Scapular muscle exercise, Balanced scapular muscle activity, Electromyography     

Influence of Hip Joint Position on Muscle Activity during Prone Hip Extension with Knee Flexion

[Purpose] This study investigated the selective activation of the gluteus maximus during a prone hip extension with knee flexion exercise, with the hip joint in different positions. [Subjects] The subjects were 21 healthy, male volunteers. [Methods] Activities of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during a prone hip extension with knee flexion exercise. Measurements were made with the hip joint in each of 3 positions: (1) a neutral hip joint position, (2) an abduction hip joint position, and (3) an abduction with external rotation hip joint position. [Results] Gluteus maximus activity was significantly higher when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. Gluteus maximus activity was also significantly higher in the abduction hip joint position than in the neutral hip joint position. Hamstring activity was significantly lower when the hip was in the abduction with external rotation hip joint position than when it was in the neutral hip joint and abduction hip joint positions. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion exercise selectively activates the gluteus maximus.Key words: Prone hip extension with knee flexion, Hip joint position, Electromyography     

Effect of abduction and external rotation of the hip joint on muscle onset time during prone hip extension with knee flexion

[Purpose] This study investigated the effect of hip position on muscle onset time during prone hip extension with knee flexion. [Subjects] The study included 21 healthy male volunteers. [Methods] Muscle onset times of the right gluteus maximus, right hamstrings, bilateral lumbar erector spinae, and bilateral lumbar multifidus were measured using surface electromyography during right hip extension with knee flexion in the prone position. Measurements were made with the hip in 3 positions: (1) neutral, (2) abduction, and (3) abduction and external rotation. [Results] Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and with hip abduction and external rotation compared with that with the hip in the neutral position. Gluteus maximus onset relative to the hamstrings was significantly earlier with hip abduction and external rotation compared with that with hip abduction. The bilateral multifidus and left lumbar erector spinae onset times relative to the hamstrings were significantly earlier with hip abduction and external rotation compared with those with hip abduction and with the hip in the neutral position. [Conclusion] Abduction and external rotation of the hip during prone hip extension with knee flexion is effective for advancing the onset times of the gluteus maximus, bilateral multifidus, and contralateral lumbar erector spinae.Key words: Prone hip extension with knee flexion, Hip joint position, Muscle onset time     

Comparative Analysis of Acromiohumeral Distances According to the Locations of the Arms and Humeral Rotation

[Purpose] The purpose of this study was to compare the potential effects of resistance exercise according to the positions of the arms and the rotation of the humerus on the subhumeral acromial space. [Subjects] The study subjects were 34 subjects without shoulder pain. [Methods] Ultrasonographic measurements of the acromiohumeral distance of the subjects were made at three shoulder positions: 90° flexion, scaption at 90° abduction, and 90° abduction in an upright sitting position. The subjects were instructed to vertically push against a table to the maximum level with the humerus in internal, neutral, and external rotation. The measurements were made three times in each position. [Results] There was a significant difference in acromiohuneral distance between neutral and internal rotation of the humerus, and between external rotation and internal rotation of the humerus. In the scaption position, there was a significant difference between neutral and internal rotation of the humerus, and between external rotation and internal rotation of the humerus. In the 90° flexion position, there was a significant difference between neutral and internal rotation, and between neutral and external rotation. There was a significant difference between the flexion position and the abduction position, and between the flexion position and the scaption position. In terms of the internal rotation of the humerus, there was a significant difference between 90° flexion and 90° abduction. [Conclusion] These findings can be applied in exercises prescribed to increase the acromiohumeral distance and to aid the treatment and evaluation of shoulder dysfunctions.Key words: Ultrasonographic, Acromiohumeral distance, Humeral rotation     

Correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students

[Purpose] This study aimed to identify correlations among pelvic positions and differences in lower extremity joint angles during walking in female university students. [Subjects] Thirty female university students were enrolled and their pelvic positions and differences in lower extremity joint angles were measured. [Methods] Pelvic position, pelvic torsion, and pelvic rotation were assessed using the BackMapper. In addition, motion analysis was performed to derive differences between left and right flexion, abduction, and external rotation ranges of hip joints; flexion, abduction, and external rotation ranges of knee joints; and dorsiflexion, inversion, and abduction ranges of ankle joints, according to X, Y, and Z-axes. [Results] Pelvic position was found to be positively correlated with differences between left and right hip flexion (r=0.51), hip abduction (r=0.62), knee flexion (r=0.45), knee abduction (r=0.42), and ankle inversion (r=0.38). In addition, the difference between left and right hip abduction showed a positive correlation with difference between left and right ankle dorsiflexion (r=0.64). Moreover, differences between left and right knee flexion exhibited positive correlations with differences between left and right knee abduction (r=0.41) and ankle inversion (r=0.45). [Conclusion] Bilateral pelvic tilt angles are important as they lead to bilateral differences in lower extremity joint angles during walking.Key words: Pelvic position, Lower extremity joint angle, Walking     

Effects of bridge exercise on trunk core muscle activity with respect to sling height and hip joint abduction and adduction

[Purpose] This study evaluated the effects of bridge exercise on trunk core muscle activity with respect to sling height and hip joint abduction and adduction. [Subjects] Fifteen healthy adult males participated. [Methods] In the bridge exercise, the height of the sling was set low or high during hip joint abduction and adduction. Electromyography was used to compare the differences between the muscle activities of the transverse abdominis, rectus abdominis, and erector spinae muscles. [Results] The muscle activities of the transverse abdominis, rectus abdominis, and erector spinae were significantly higher in the high sling position. Furthermore, the activities of the transverse abdominis and erector spinae were significantly higher during hip joint adduction than abduction regardless of sling height. [Conclusion] A high sling height is the most effective intervention for increasing the muscle activities of the transverse abdominis and erector spinae muscles during hip joint adduction in a bridge exercise.Key words: Bridge exercise, Trunk core muscle, Sling     

Joint Range of Motion in Flaccid Hemiplegia

The effect of muscle tone on passive range of motion (PROM) in affected joints and comparison joints on the unaffected side was investigated in 15 patients with flaccid paralysis hemiplegia. PROM was measured in the shoulder and hip in flexion, extension, abduction, adduction and internal and external rotation using the plastic universal goniometer. PROM in the elbow and knee was assessed in flexion and extension. Wrist PROM was measured in flexion, extension and radial and ulnar deviation. Additionally, ankle dorsiflexion, plantarflexion, eversion and inversion PROM were assessed. Decreased muscle tone significantly affected shoulder (p = 0.006), wrist (p = 0.032) and hip (p = 0.003) PROM. Significant differences between the affected and unaffected sides were found in shoulder PROM in extension (p = 0.014), adduction (p = 0.001) and internal (p = 0.034) and external rotation (p = 0.007). Wrist PROM was significantly different in flexion (p = 0.048) and extension (p = 0.001), and hip PROM was significantly different in abduction (p = 0.029), adduction (p = 0.012) and external rotation (p = 0.001). Surprisingly, although muscle tone had no influence on ankle PROM, there was a significant difference in ankle plantarflexion PROM (p = 0.013). In conclusion, in flaccid hemiplegia, decreased muscle tone affects the PROM in the shoulder, wrist and hip. Differences in PROM between the unaffected and affected side are evident in shoulder extension, adduction and internal and external rotation, wrist flexion and extension, hip abduction, adduction and external rotation, and ankle plantarflexion.     

EMG Activity in the Abdominal Muscles and the Kinematics of the Lumbar Spine during Unilateral Upper-limb Resistance Exercises under Stable and Unstable Conditions

[Purpose] We investigated the effects of unstable conditions on the electromyographic (EMG) activity of the rectus abdominis (RA) and the transverse abdominis–internal oblique (TrA-IO) muscles, and lumbar kinematics during unilateral upper-limb resistance exercises using elastic tubing bands. [Subjects] Twelve healthy males were recruited. [Methods] The subjects performed isometric left shoulder abduction using an elastic tubing band in a sitting position on a chair, and on a Swiss ball. During this exercise, EMG activities of the RA and TrA-IO were recorded using a wireless EMG system, and a three-dimensional motion analysis system monitored lumbar kinematics. Differences in EMG activities of the RA and TrA-IO, the ratio of TrA-IO to RA activity, and lumbar kinematics were compared between the stable and unstable conditions using the paired t-test. [Results] Under the unstable condition, the EMG activities of both muscles were significantly greater than that under the stable condition; however the ratio of TrA-IO to RA activity did not significantly differ between the conditions. The lumbar angle significantly differed only in the coronal plane. [Conclusions] These findings indicate that trunk posture should be considered when performing exercises under unstable conditions.Key words: Swiss ball, Abdominal muscles, Electromyography     

The Effects of Knee Joint and Hip Abduction Angles on the Activation of Cervical and Abdominal Muscles during Bridging Exercises

[Purpose] The purpose of this study was to examine the effects of the flexion angle of the knee joint and the abduction angle of the hip joint on the activation of the cervical region and abdominal muscles. [Subjects] A total of 42 subjects were enrolled 9 males and 33 females. [Methods] The bridging exercise in this study was one form of exercise with a knee joint flexion angle of 90°. Based on this, a bridging exercise was conducted at the postures of abduction of the lower extremities at 0, 5, 10, and 15°. [Result] The changes in the knee joint angle and the hip abduction angle exhibited statistically significant effects on the cervical erector spinae, adductor magnus, and gluteus medius muscles. The abduction angles did not result in statistically significant effects on the upper trapezium, erector spinae, external oblique, and rectus abdominis muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. [Conclusion] When patients with both cervical and back pain do a bridging exercise, widening the knee joint angle would reduce cervical and shoulder muscle activity through minimal levels of abduction, permitting trunk muscle strengthening with reduced cervical muscle activity. This method would be helpful for strengthening trunk muscles in a selective manner.Key words: Bridging exercise, Knee and hip joint angle, Muscle activation     

The Immediate Effect of Humerus Anatomical Neck-shaft Rotation on Glenohumeral Joint Contracture

[Purpose] Elderly female patients with glenohumeral joint (GHJ) contracture, forced into prolonged immobility were examined. Range of motion exercises using humerus anatomical neck-shaft rotation were performed, and the immediate effect and adaptation were investigated. [Subjects and Methods] A total of ten individuals with a mean age of 79.4 ± 11.0 years were included in this study. The controlled intervention involved conventional range of motion exercises, and the experimental intervention involved humerus anatomical neck-shaft rotation. Each exercise was performed 30 times. Shoulder joint flexion and abduction and external rotation of the GHJ range of motion were measured with the scapula fixed. Each change in range of motion was compared using ANOVA; less than 5% was considered significant. [Results] After the experimental intervention, significant increases were seen in shoulder joint flexion, abduction, and external rotation ranges of motion. [Conclusion] Therefore, this method was effective as a means of improving the range of motion of the GHJ.Key words: Shoulder joint, Contracture, Humerus anatomical neck-shaft rotation     

Examining Muscle Activity Differences During Single and Dual Vector Elastic Resistance Exercises

BackgroundElastic resistance exercise is a common part of rehabilitation programs. While these exercises are highly prevalent, little information exists on how adding an additional resistance vector with a different direction from the primary vector alters muscle activity of the upper extremity.PurposeThe purpose of this study was to examine the effects of dual vector exercises on torso and upper extremity muscle activity in comparison to traditional single vector techniques.Study DesignRepeated measures design.MethodsSixteen healthy university-aged males completed four common shoulder exercises against elastic resistance (abduction, flexion, internal rotation, external rotation) while using a single or dual elastic vector at a fixed cadence and standardized elastic elongation. Surface electromyography was collected from 16 muscles of the right upper extremity. Mean, peak and integrated activity were extracted from linear enveloped and normalized data and a 2-way repeated measures ANOVA examined differences between conditions.ResultsAll independent variables differentially influenced activation. Interactions between single/dual vectors and exercise type affected mean activation in 11/16 muscles, while interactions in peak activation existed in 7/16 muscles. Adding a secondary vector increased activation predominantly in flexion or abduction exercises; little changes existed when adding a second vector in internal and external rotation exercises. The dual vector exercise in abduction significantly increased mean activation in lower trapezius by 25.6 ± 8.11 %MVC and peak activation in supraspinatus by 29.4 ± 5.94 %MVC (p<0.01). Interactions between single/dual vectors and exercise type affected integrated electromyography for most muscles; the majority of these muscles had the highest integrated electromyography in the dual vector abduction condition.ConclusionMuscle activity often increased with a second resistance vector added; however, the magnitude was exercise-dependent. The majority of these changes existed in the flexion and abduction exercises, with little differences in the internal or external rotation exercises.Level of Evidence3b     

Goniometric reliability in a clinical setting. Shoulder measurements

The purpose of this study was to examine the intratester and intertester reliabilities for clinical goniometric measurements of shoulder passive range of motion (PROM) using two different sizes of universal goniometers. Patients were measured without controlling therapist goniometric placement technique or patient position during measurements. Repeated PROM measurements of shoulder flexion, extension, abduction, shoulder horizontal abduction, horizontal adduction, lateral (external) rotation, and medial (internal) rotation were taken of two groups of 50 subjects each. The intratester intraclass correlation coefficients (ICCs) for all motions ranged from .87 to .99. The ICCs for the intertester reliability of PROM measurements of horizontal abduction, horizontal adduction, extension, and medial rotation ranged from .26 to .55. The intertester ICCs for PROM measurements of flexion, abduction, and lateral rotation ranged from .84 to .90. Goniometric PROM measurements for the shoulder appear to be highly reliable when taken by the same physical therapist, regardless of the size of the goniometer used. The degree of intertester reliability for these measurements appears to be range-of-motion specific.     

Comparison of the Tibialis Anterior and Soleus Muscles Activities during the Sit-to-stand Movement with Hip Adduction and Hip Abduction in Elderly Females

[Purpose] The purpose of this study was to compare the activation of the tibialis anterior (TA) and soleus (SOL) muscles during the sit-to-stand (STS) task with hip adduction and hip abduction in elderly females. [Subjects] We recruited 16 healthy elderly females with no pain in the knee joint and no other orthopedic problems of the lower limbs. [Methods] The activities of the dominant lower extremity muscles were measured using a wireless electromyography (EMG) system. Subjects then performed a total of nine STS trials, including three trials each for hip adduction, hip abduction, and natural STS tasks. [Results] In the pre- thigh-off (TO) phase, the normalized EMG data of the TA muscle increased significantly when the STS task was performed with hip adduction compared with hip abduction. In the post-TO phase, the normalized EMG data of the TA muscle showed a significant increase during the STS task with hip adduction compared with hip abduction. Additionally, the normalized EMG data of the SOL muscle increased significantly when the STS task was performed with hip adduction compared with hip abduction. [Conclusion] Therefore, the STS movement with hip adduction poses a greater challenge for balance control, indicating that certain elderly individuals would have difficulty in executing an abrupt adjustment in their dynamic postural stability during the STS movement.Key words: Sit-to-stand, Hip adduction, Hip abduction     

膏摩治疗配合等速训练治疗肩周炎的疗效观察

目的:观察膏摩结合等速训练治疗肩周炎的临床疗效。方法:将60名肩周炎患者随机分为观察组和对照组各30例,2组均采用膏摩治疗,观察组加用等速肌力训练。观察2组患者治疗前后肩关节前屈、后伸,外展角度、力矩峰值及VAS评分变化。结果:治疗3周后,2组患者肩关节前屈、后伸、外展角度及力矩峰值均较治疗前明显提高(P0.05),且观察组更优于对照组(P0.05);2组VAS评分均较治疗前明显下降(P0.05),且观察组更低于对照组(P0.05)。结论:膏摩治疗配合等速训练能够更好的减轻肩周炎患者的疼痛,增加肩关节活动度,增加肌力,并藉此改善患者上肢运动功能。     

Upper extremity strength and range of motion and their relationship to function in breast cancer survivors

The impact upper extremity impairments (UE) have on UE function in breast cancer survivors (BCS) is unclear. The purpose of this study was to evaluate the associations between upper extremity active range of motion (AROM), passive range of motion (PROM), and strength with self-reported function in BCS. BCS (n = 24) completed the Disabilities of Arm, Shoulder and Hand (DASH) and the Pennsylvania Shoulder Score (PSS). AROM and PROM of shoulder flexion, extension, external rotation (ER) at 0° and 90° of abduction, and internal rotation (IR) at 90° of abduction were measured using a digital inclinometer. Strength was measured using a hand-held dynamometer for scapular abduction and upward rotation, scapular depression and adduction, flexion, IR, ER, scaption, and horizontal adduction. All constructs of AROM, PROM, and strength were correlated with the DASH and PSS. DASH was moderately to highly correlated with 2 of 5 AROM, 2 of 5 PROM, and 6 of 7 shoulder strength measures. PSS was moderately to highly correlated with 2 of 5 AROM, 2 of 5 PROM, and 4 of 7 shoulder strength measures. Regression analysis showed that AROM explained 40% of the DASH scores and strength explained 20% of scores on the PSS. This study characterizes the impact that shoulder motion, flexibility, and strength losses have on shoulder function in BCS. Deficits in AROM and shoulder strength explained the greatest proportion of shoulder disability. Future clinical trials should consider incorporating AROM and strengthening techniques to improve shoulder use after breast cancer treatments.     

Changes in Shoulder External Rotator Muscle Activity during Shoulder External Rotation in Various Arm Positions in the Sagittal Plane

[Purpose] The aim of this study was to investigate changes in electromyographic (EMG) activity of the infraspinatus and posterior deltoid muscles during shoulder external rotation under different shoulder flexion angles. [Subjects] Thirteen participants were included in this study. [Methods] The participants performed isometric shoulder external rotation at 45°, 90°, and 135° of shoulder flexion. A surface EMG system recorded the EMG activity of the infraspinatus and posterior deltoid muscles during shoulder external rotation. The changes in the muscle activity of infraspinatus and posterior deltoid and ratio of infraspinatus to posterior deltoid muscle activity were analyzed using one-way repeated-measures analysis of variance with Bonferroni’s correction. [Results] The posterior deltoid activity was significantly decreased, while the ratio of the infraspinatus to posterior deltoid activity was significantly increased at 45° of shoulder flexion compared with 90° and 135° of shoulder flexion (p < 0.05). There were no significant differences in the EMG activity of the infraspinatus among the three conditions (p > 0.05). [Conclusion] These findings indicate that shoulder external rotation at 45° of shoulder flexion effectively reduced the contribution of the posterior deltoid activation to shoulder external rotation.Key words: Infraspinatus, Posterior deltoid, Shoulder external rotation     

Slow Expiration Reduces External Oblique Muscle Activity during Maximum Trunk Flexion

[Purpose] The purpose of this study was to demonstrate the effects of expiration on abdominal muscle activity during maximum trunk flexion. [Subjects] Twenty-one healthy university students (10 men, 11 women) participated in this study. [Methods] Electromyography (EMG) was used to quantify the activity of the right rectus abdominis, external oblique, and internal oblique muscles. The paired t-test was used to examine the significance of differences in the abdominal muscles between maximum trunk flexion with breath holding and slow expiration. [Results] There was a significantly lower EMG activity in the external oblique muscle during maximum trunk flexion with slow expiration. [Conclusion] The results of this study indicate that slow expiration reduces external oblique muscle activity during maximum trunk flexion performed by healthy young subjects.Key words: Expiration, Electromyography, Abdominal muscles     

The Influence of an Unstable Surface on Trunk and Lower Extremity Muscle Activities during Variable Bridging Exercises

[Purpose] The aim of this study was to investigate the influence of an unstable surface on trunk and lower extremity muscle activities during various types of bridging exercises. [Subjects] Thirty healthy female adults voluntarily participated in this study. [Methods] All subjects were asked to perform 3 different bridging exercises (bridging exercise, single leg lift bridging exercise, single leg cross bridging exercise) with and without an unstable surface. The trunk and lower extremity muscle activities were measured by using surface electromyography during bridging exercise. [Results] During the bridging exercise (BE), single leg lift bridging exercise (LBE), and single leg cross bridging exercise (CBE), the muscle activities of the external oblique muscle (EO), erector spinae (ES), and biceps femoris (BF) were significantly higher on an unstable surface than on a stable surface. The muscle activities of the EO on both sides, contralateral BF, and ipsilateral ES were significantly higher during LBE than during BE and CBE. [Conclusion] Use of an unstable surface increases muscle activity of the trunk and lower extremities, and single leg lift bridging exercise increases the muscle activity of the EO on both sides, ipsilateral ES, and contralateral BF.Key words: Bridging exercise, Electromyography, Unstable surface