Effects of 3 Infraspinatus Muscle Strengthening Exercises on Isokinetic Peak Torque and Muscle Activity

2019 ◽  
Vol 28 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Il-young Yu ◽  
Dong-kyu Lee ◽  
Myoung-Joo Kang ◽  
Jae-seop Oh
Keyword(s):  
Muscle Strength ◽  
Muscle Contraction ◽  
Muscle Activity ◽  
Repeated Measures ◽  
External Rotation ◽  
Peak Torque ◽  
Deltoid Muscle ◽  
Repeated Measures Design ◽  
Infraspinatus Muscle ◽  
Main Effect

Context: The infraspinatus muscle plays a particularly important role in producing primary external rotation (ER) torque and dynamic stability of the shoulder joint. Previous studies have reported that prone external rotation with horizontal abduction (PER), side-lying wiper exercise (SWE), and standing external rotation (STER) were effective exercises for strengthening the infraspinatus. However, we do not have enough knowledge about changes in muscle strength and dynamic muscle activity in each exercise under dynamic conditions. Objective: To compare the ER muscle strength, muscle activity among exercise methods and between muscle contraction types during 3 different exercises. Design: Repeated measures design in which ER muscle strength and muscle activities data were collected from subjects under 3 exercise conditions. Setting: Outpatient clinic. Participants: A total of 15 healthy men with no shoulder, neck, or upper-extremity pain were participated. Intervention: The subjects performed 3 different exercises randomly in concentric and eccentric using a Biodex dynamometer at an angular velocity of 60°/s. Main Outcome Measures: The ER peak torque (PT) data was collected and surface electromyography was used to measure the activity of the infraspinatus and posterior deltoid muscles and infraspinatus to posterior deltoid muscle activity ratio. Results: There was significant main effect for muscle contraction type in ER PT (P < .05). The concentric PT was greater during PER (P < .05) and SWE (P < .05) compared with eccentric. The main effect for exercise was found in ER PT and muscle activity (P < .05). The ER PT and infraspinatus muscle activity were the largest increased during PER whereas the lowest during STER in both concentric and eccentric (P < .05). Conclusion: The results of this study suggest that PER is an exercise for strengthening the infraspinatus muscle effectively.

scholarly journals Selective Activation of the Infraspinatus Muscle

2013 ◽  
Vol 48 (3) ◽  
pp. 346-352 ◽  
Author(s):  
Sung-Min Ha ◽  
Oh-Yun Kwon ◽  
Heon-Seock Cynn ◽  
Won-Hwee Lee ◽  
Su-Jung Kim ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
External Rotation ◽  
Trapezius Muscle ◽  
Deltoid Muscle ◽  
Limited Information ◽  
Cross Sectional ◽  
Bonferroni Adjustment ◽  
Infraspinatus Muscle ◽  
Shoulder External Rotation

Context: To improve selective infraspinatus muscle strength and endurance, researchers have recommended selective shoulder external-rotation exercise during rehabilitation or athletic conditioning programs. Although selective strengthening of the infraspinatus muscle is recommended for therapy and training, limited information is available to help clinicians design a selective strengthening program. Objective: To determine the most effective of 4 shoulder external-rotation exercises for selectively stimulating infraspinatus muscle activity while minimizing the use of the middle trapezius and posterior deltoid muscles. Design: Cross-sectional study. Setting: University research laboratory. Patients or Other Participants: A total of 30 healthy participants (24 men, 6 women; age = 22.6 ± 1.7 years, height = 176.2 ± 4.5 cm, mass = 65.6 ± 7.4 kg) from a university population. Intervention(s): The participants were instructed to perform 4 exercises: (1) prone horizontal abduction with external rotation (PER), (2) side-lying wiper exercise (SWE), (3) side-lying external rotation (SER), and (4) standing external-rotation exercise (STER). Main Outcome Measure(s): Surface electromyography signals were recorded from the infraspinatus, middle trapezius, and posterior deltoid muscles. Differences among the exercise positions were tested using a 1-way repeated-measures analysis of variance with Bonferroni adjustment. Results: The infraspinatus muscle activity was greater in the SWE (55.98% ± 18.79%) than in the PER (46.14% ± 15.65%), SER (43.38% ± 22.26%), and STER (26.11% ± 15.00%) (F3,87 = 19.97, P &lt; .001). Furthermore, the SWE elicited the least amount of activity in the middle trapezius muscle (F3,87 = 20.15, P &lt; .001). Posterior deltoid muscle activity was similar in the SWE and SER but less than that measured in the PER and STER (F3,87 = 25.10, P &lt; .001). Conclusions: The SWE was superior to the PER, SER, and STER in maximizing infraspinatus activity with the least amount of middle trapezius and posterior deltoid activity. These findings may help clinicians design effective exercise programs.

Effects of Bracing on Isokinetic Torque for the Chronically Unstable Ankle

1999 ◽  
Vol 8 (2) ◽  
pp. 83-98 ◽  
Author(s):  
Heather D. Hartsell ◽  
Sandi J. Spaulding
Keyword(s):  
Muscle Contraction ◽  
Repeated Measures ◽  
Peak Torque ◽  
Joint Motion ◽  
Repeated Measures Design ◽  
Isokinetic Torque ◽  
Contraction Type

Because the effects of bracing on dynamic torque production are unknown, the purpose of this study was to determine the effects of flexible and semirigid braces on isokinetic torque production at varying velocities produced by the invertor and evertor muscles for the chronically unstable ankle. Ten healthy and 14 chronically unstable ankles were tested, with a repeated-measures design including joint motion (inversion, eversion), muscle contraction type (concentric, eccentric), brace condition (unbraced, flexible, semirigid), and velocity (60, 120, 180, 240°/s). Multiple ANOVAs with repeated-measures and Bonferroni-adjusted comparisons were performed. Results showed that the chronically unstable ankle was significantly weaker than the healthy ankle, regardless of muscle contraction type or joint motion, and that bracing did not deter the muscles' ability to produce peak torque either concentrically or eccentrically. The chronically unstable ankle requires enhanced strengthening, particularly eccentrically and at higher, more functional velocities. Bracing can reduce or prevent injury to the ankle without deterring torque production.

scholarly journals Submaximal Elastic Resistance Band Tests to Estimate Upper and Lower Extremity Maximal Muscle Strength

2021 ◽  
Vol 18 (5) ◽  
pp. 2749
Author(s):  
Bjarki T. Haraldsson ◽  
Christoffer H. Andersen ◽  
Katrine T. Erhardsen ◽  
Mette K. Zebis ◽  
Jéssica K. Micheletti ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Lower Extremity ◽  
Relative Intensity ◽  
Repeated Measures ◽  
External Rotation ◽  
Shoulder Abduction ◽  
Strength Assessment ◽  
Repeated Measures Design ◽  
Elastic Resistance ◽  
Maximal Muscle Strength

Muscle strength assessment is fundamental to track the progress of performance and prescribe correct exercise intensity. In field settings, simple tests are preferred. This study develops equations to estimate maximal muscle strength in upper- and lower-extremity muscles based on submaximal elastic resistance tests. Healthy adults (n = 26) performed a maximal test (1 RM) to validate the ability of the subsequent submaximal tests to determine maximal muscle strength, with elastic bands. Using a within-group repeated measures design, three submaximal tests of 40%, 60%, and 80% during (1) shoulder abduction, (2) shoulder external rotation, (3) hip adduction, and (4) prone knee flexion were performed. The association between number of repetitions and relative intensity was modeled with both 1st and 2nd order polynomials to determine the best predictive validity. For both upper-extremity tests, a strong linear association between repetitions and relative intensity was found (R2 = 0.97–1.00). By contrast, for the lower-extremity tests, the associations were fitted better with a 2nd order polynomial (R2 = 1.00). The results from the present study provide formulas for predicting maximal muscles strength based on submaximal resistance in four different muscles groups and show a muscle-group-specific association between repetitions and intensity.

scholarly journals Effects of Pitch and Rhythm Priming Tasks on Accuracy and Fluency During Sight-Reading

2019 ◽  
Vol 67 (3) ◽  
pp. 252-269
Author(s):  
Christine R. Russell
Keyword(s):  
Repeated Measures ◽  
Sight Reading ◽  
Exposure Condition ◽  
Pitch Accuracy ◽  
Wind Instrumentalists ◽  
Repeated Measures Design ◽  
Priming Condition ◽  
Main Effect ◽  
Main Effects ◽  
Performance Scale

The purpose of this study was to investigate the effects of pitch and rhythm priming tasks on sight-reading accuracy and fluency. High school wind instrumentalists ( N = 182) were assigned to one of four experimental groups: pre-/posttest rhythm, pre-/posttest pitch, posttest-only rhythm, or posttest-only pitch. Participants sight-read selected stimulus exercises from the Watkins-Farnum Performance Scale and completed two priming treatments and a control condition as part of a repeated-measures design. A three-way repeated-measures MANOVA, with rhythm accuracy, pitch accuracy, and fluency accuracy as dependent measures, revealed a significant main effect due to priming condition. Rhythm accuracy scores were significantly lower after both perceptual and conceptual priming than after a control condition. No significant differences in pitch accuracy or fluency existed based on priming condition. No significant differences were found in rhythm, pitch, or fluency accuracy based on treatment condition (pitch or rhythm) or exposure condition (pre-/posttest or post only). Two-way repeated-measures MANOVAs revealed significant main effects based on time. Pitch accuracy and fluency each significantly improved between pre- and posttest and from the first to third study tasks. Results suggest that performing rhythm alone or pitch alone requires different cognitive processes than does performing both together.

scholarly journals Hip Muscle Activity During 3 Side-Lying Hip-Strengthening Exercises in Distance Runners

2012 ◽  
Vol 47 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Joseph M. McBeth ◽  
Jennifer E. Earl-Boehm ◽  
Stephen C. Cobb ◽  
Wendy E. Huddleston
Keyword(s):  
Muscle Activity ◽  
Repeated Measures ◽  
External Rotation ◽  
Gluteus Maximus ◽  
Gluteus Medius ◽  
Electromyographic Activity ◽  
Maximal Voluntary Isometric Contraction ◽  
Strengthening Exercises ◽  
Hip Abduction ◽  
Hip Strengthening

Context: Lower extremity overuse injuries are associated with gluteus medius (GMed) weakness. Understanding the activation of muscles about the hip during strengthening exercises is important for rehabilitation. Objective: To compare the electromyographic activity produced by the gluteus medius (GMed), tensor fascia latae (TFL), anterior hip flexors (AHF), and gluteus maximus (GMax) during 3 hip-strengthening exercises: hip abduction (ABD), hip abduction with external rotation (ABD-ER), and clamshell (CLAM) exercises. Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: Twenty healthy runners (9 men, 11 women; age = 25.45 ± 5.80 years, height = 1.71 ± 0.07 m, mass = 64.43 ± 7.75 kg) participated. Intervention(s): A weight equal to 5% body mass was affixed to the ankle for the ABD and ABD-ER exercises, and an equivalent load was affixed for the CLAM exercise. A pressure biofeedback unit was placed beneath the trunk to provide positional feedback. Main Outcome Measure(s): Surface electromyography (root mean square normalized to maximal voluntary isometric contraction) was recorded over the GMed, TFL, AHF, and GMax. Results: Three 1-way, repeated-measures analyses of variance indicated differences for muscle activity among the ABD (F3,57 = 25.903, P&lt;.001), ABD-ER (F3,57 = 10.458, P&lt;.001), and CLAM (F3,57 = 4.640, P=.006) exercises. For the ABD exercise, the GMed (70.1 ± 29.9%), TFL (54.3 ± 19.1%), and AHF (28.2 ± 21.5%) differed in muscle activity. The GMax (25.3 ± 24.6%) was less active than the GMed and TFL but was not different from the AHF. For the ABD-ER exercise, the TFL (70.9 ± 17.2%) was more active than the AHF (54.3 ± 24.8%), GMed (53.03 ± 28.4%), and GMax (31.7 ± 24.1 %). For the CLAM exercise, the AHF (54.2 ± 25.2%) was more active than the TFL (34.4 ± 20.1%) and GMed (32.6 ± 16.9%) but was not different from the GMax (34.2 ± 24.8%). Conclusions: The ABD exercise is preferred if targeted activation of the GMed is a goal. Activation of the other muscles in the ABD-ER and CLAM exercises exceeded that of GMed, which might indicate the exercises are less appropriate when the primary goal is the GMed activation and strengthening.

Spatial Representation in Blind Children. 2: Effects of Task Variations

1981 ◽  
Vol 75 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Janet F. Fletcher
Keyword(s):  
Repeated Measures ◽  
Spatial Representation ◽  
Or Efficiency ◽  
Repeated Measures Design ◽  
Free Exploration ◽  
Room Size ◽  
Spatial Tasks ◽  
Blind Children ◽  
Main Effect ◽  
Reported Study

In the literature on spatial representation in blind people, several parameters of spatial tasks have been used as controlled variables without due consideration of the effects they might have on the type or efficiency of subjects’ spatial representation. Two such variables are the size of the object or environment to be represented and the degree of freedom allowed subjects in their exploration of these objects or environments. Data about the blind subjects of the author's previously reported study on spatial representation in blind children were further analyzed using a three-way repeated-measures design to determine the effect of room size and exploration mode in response to questions about the position of furniture in a room. Neither variable produced a significant main effect. The responses of subjects in the free-exploration condition were further analyzed to determine the effect on performance of the actual exploration strategy. In the first trial of the task, the exploration route that corresponded to the route previously used to introduce subjects to the empty room was the most successful strategy. By the final trial, the differences among strategies had decreased. Organized strategies, however, were found to be more successful than random movement.

scholarly journals Reliability of Isometric and Eccentric Isokinetic Shoulder External Rotation

2016 ◽  
Vol 25 (2) ◽  
Author(s):  
Brianna M. Papotto ◽  
Thomas Rice ◽  
Terry Malone ◽  
Timothy Butterfield ◽  
Tim L. Uhl
Keyword(s):  
Repeated Measures ◽  
External Rotation ◽  
High Reliability ◽  
Peak Torque ◽  
Total Work ◽  
Isokinetic Testing ◽  
Deceleration Phase ◽  
Shoulder Muscles ◽  
Shoulder External Rotation ◽  
Average Angle

Context: Shoulder external rotators are challenged eccentrically throughout the deceleration phase of throwing, which is thought to contribute to overuse injuries. To evaluate the effectiveness of intervention programs, as well as identifying deficits, reliable and responsive measures of isometric and eccentric shoulder external rotation are necessary. Previously, isometric measures have primarily tested a single position, and eccentric measures have not been found to have high reliability. Objective: To examine the between-days reliability of multiple-angle isometric and dynamic eccentric isokinetic testing of shoulder external rotation. Design: Repeated measures. Participants: 10 healthy subjects (age 30 ± 12 y, height 166 ± 13 cm, mass 72 ± 10 kg). Main Outcome Measures: Average isometric peak torque of shoulder external rotation at 7 angles was measured. From these values, the angle of isometric peak torque was calculated. Dynamic eccentric average peak torque, average total work, and average angle of peak torque were measured. Results: Between-days reliability was high for average peak torque during isometric contractions at all angles (ICC ≥ .85), as it was for dynamic eccentric average peak torque (ICC ≥ .97). The estimated angle of isometric peak torque (ICC ≤ .65) was not highly reliable between days. The average angle of peak torque from the eccentric testing produced inconsistent results. Average total work of dynamic eccentric shoulder external rotation was found to be highly reliable between days (ICC ≥ . 97). Conclusion: Aspects of force such as peak torque and total work in isometric and eccentric testing of the shoulder external-rotator muscles can be measured reliably between days and used to objectively evaluate shoulder strength and identify changes when they occur. Angle measurements of peak torque could provide insight into the mechanical properties of the posterior shoulder muscles but were found to be inconsistent between days.

scholarly journals Shoulder Kinematics Is Not Influenced by External Load During Elevation in the Scapular Plane

2014 ◽  
Vol 30 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Marcelo P. de Castro ◽  
Daniel Cury Ribeiro ◽  
Felipe de C. Forte ◽  
Joelly M. de Toledo ◽  
Daniela Aldabe ◽  
...  
Keyword(s):  
Repeated Measures ◽  
External Load ◽  
External Rotation ◽  
Angular Displacement ◽  
Neutral Position ◽  
Convenience Sample ◽  
Repeated Measures Design ◽  
Shoulder Kinematics ◽  
Shoulder Elevation ◽  
Scapular Plane

The current study aimed to compare the shoulder kinematics (3D scapular orientation, scapular angular displacement and scapulohumeral rhythm) of asymptomatic participants under unloaded and loaded conditions during unilateral shoulder elevation in the scapular plane. We used a repeated-measures design with a convenience sample. Eleven male participants with an age range of 21–28 years with no recent history of shoulder injury participated in the study. The participants performed isometric shoulder elevation from a neutral position to approximately 150 degrees of elevation in the scapular plane in intervals of approximately 30 degrees during unloaded and loaded conditions. Shoulder kinematic data were obtained with videogrammetry. During shoulder elevation, the scapula rotated upwardly and externally, and tilted posteriorly. The addition of an external load did not affect 3D scapular orientation, scapular angular displacement, or scapulohumeral rhythm throughout shoulder elevation (P> .05). In clinical practice, clinicians should expect to observe upward and external rotation and posterior tilt of the scapula during their assessments of shoulder elevation. Such behavior was not influenced by an external load normalized to 5% of body weight when performed in an asymptomatic population.

Electromyographic Evaluation of Abdominal-Muscle Function With and Without Concomitant Pelvic-Floor-Muscle Contraction

2013 ◽  
Vol 22 (2) ◽  
pp. 108-114 ◽  
Author(s):  
Nahid Tahan ◽  
Amir Massoud Arab ◽  
Bita Vaseghi ◽  
Khosro Khademi
Keyword(s):  
Pelvic Floor ◽  
Muscle Contraction ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Pelvic Floor Muscle ◽  
Abdominal Muscle ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Repeated Measures Design ◽  
Emg Signal

Context:Coactivation of abdominal and pelvic-floor muscles (PFM) is an issue considered by researchers recently. Electromyography (EMG) studies have shown that the abdominal-muscle activity is a normal response to PFM activity, and increase in EMG activity of the PFM concomitant with abdominal-muscle contraction was also reported.Objective:The purpose of this study was to compare the changes in EMG activity of the deep abdominal muscles during abdominal-muscle contraction (abdominal hollowing and bracing) with and without concomitant PFM contraction in healthy and low-back-pain (LBP) subjects.Design:A 2 × 2 repeated-measures design.Setting:Laboratory.Participants:30 subjects (15 with LBP, 15 without LBP).Main Outcome Measures:Peak rectified EMG of abdominal muscles.Results:No difference in EMG of abdominal muscles with and without concomitant PFM contraction in abdominal hollowing (P = .84) and abdominal bracing (P = .53). No difference in EMG signal of abdominal muscles with and without PFM contraction between LBP and healthy subjects in both abdominal hollowing (P = .88) and abdominal bracing (P = .98) maneuvers.Conclusion:Adding PFM contraction had no significant effect on abdominal-muscle contraction in subjects with and without LBP.

scholarly journals Denervation of the infraspinatus and release of the posterior deltoid muscles in the management of dyskinetic external shoulder rotation in cerebral palsy

2015 ◽  
Vol 15 (4) ◽  
pp. 438-444
Author(s):  
Izabela Blaszczyk ◽  
Anna Cecilia Granström ◽  
Mikael Wiberg
Keyword(s):  
Cerebral Palsy ◽  
Botulinum Toxin ◽  
External Rotation ◽  
Botulinum Toxin A ◽  
Posterior Part ◽  
Deltoid Muscle ◽  
Toxin A ◽  
Video Recordings ◽  
Infraspinatus Muscle ◽  
Treatment Alternatives

OBJECT The dyskinetic subtype of cerebral palsy is difficult to manage, and there is no established gold standard for treatment. External rotation of the shoulder(s) is often managed nonsurgically using injections of botulinum toxin A into the external rotator muscles. This article reports a new surgical technique for managing external rotation when botulinum toxin A treatment is not sufficient or possible. METHODS Six patients with dyskinetic cerebral palsy underwent denervation of the infraspinatus muscle and release of the posterior part of the deltoid muscle. Postoperative questionnaires were given to the patients/caregivers, and video recordings were made both pre- and postoperatively. Preoperative and postoperative Assisting Hand Assessment was possible in only 1 case. RESULTS Five patients were very satisfied with their outcome. Four patients' video recordings showed improvement in their condition. One patient developed postoperative complications. CONCLUSIONS The results indicate that denervation of the infraspinatus muscle and posterior deltoid release can be an option for patients with dyskinetic cerebral palsy to manage external rotation of the shoulder when other treatment alternatives are insufficient.

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