When designing work tasks, one goal should be to enable postures that maximize the force capabilities of the workers while minimizing the overall muscular demands; however, little is known regarding specific shoulder tissue loads during pushing and pulling. This study quantitatively evaluated the effects of direction (anterior-posterior pushing and pulling), handle height (100 cm and 150 cm), handle orientation (vertical and horizontal), included elbow angle (extended and flexed) as well as personal factors (gender, mass and stature) on hand force magnitudes, shoulder and L5/S1 joint moments, normalized mean muscle activation and electromyography (EMG)/force ratios during two-handed maximal push and pull exertions. Twelve female and twelve male volunteers performed maximal voluntary isometric contractions under 10 push and pull experimental conditions that emulated industrial tasks. Hand force magnitudes, kinematic data and bilateral EMG of seven superficial shoulder and trunk muscles were collected. Results showed that direction had the greatest influence on dependent measures. Push exertions produced the greatest forces while also reducing L5/S1 extensor moments, shoulder moments with the 150 cm height and overall muscular demands (p < 0.0001). The 100 cm handle height generated the greatest forces (p < 0.0001) and reduced muscular demands (p < 0.05), but were associated with greater sagittal plane moments (p < 0.05). Females generated, on average, 67% of male forces in addition to incurring greater muscular demands (p < 0.05). The flexed elbows condition in conjunction with pushing produced greater forces with reduced overall muscular demands (p < 0.0001). Furthermore, horizontal handle orientation caused greater resultant moments at all joints (p <. 0.05) The results have important ergonomics implications for evaluating, designing or modifying workstations, tasks or equipment towards improved task performance and the prevention of musculoskeletal injuries and associated health care costs.

A lot of patients come to consult different doctors because of the shoulder aches. In order to help them the right diagnosis should be known. After degenerative or traumatic lesions, if it‘s done in a timely matter, surgical treatment is very affective. But for further progress a big role is being plaid by physical therapy. It helps the patients to restore lost function of the shoulder. After analysing some literature, I noticed that insufficient attention is being spared to the role of physical therapy in the early post surgical period, so I decided to gert a deeper view of this topic. The aim of this study was to evaluate the effectiveness of physical therapy in the early period after the surgery of the rotator cuff. The goals of the study: 1. to evaluate the effectiveness of physical therapy on the subjective criteria of a shoulder in the early period after the surgery; 2. to estimate the change of the amplitude in the shoulder’s muscle and changes of shoulder retraction force using physical therapy in the early period after the surgery. Organization and methods of the study. 36 patients who were after the rotator cuff split surgery underwent examination. Physical therapy was used at rehabilitation department of Kaunas Red Cross Hospital in 2004-2005. The evaluation of results was based on the Constant scale. The results were evaluated six and eight weeks after the surgery. The patients were grouped into two groups. Each group consisted of ten men and eight women age 54... [to full text]

Submitted in partial compliance with the requirements for the Masters Degree in Technology: Chiropractic at the Durban University of Technology, 2009. / Aim: The aim of the study was to assess the effect of a single versus multiple cervical spine manipulations, over a two week period, on peak torque of the rotator cuff muscles utilizing the Cybex Orthotron II Isokinetic Rehabilitation System. This study was a pre and post experimental investigation. Method: Forty asymptomatic (in terms of neck and shoulder pain) male chiropractic students were stratified into two equal groups of twenty subjects to ensure that each group consisted of an equal number of subjects from each year of study. All subjects underwent a familiarisation session on the Cybex Orthotron II Isokinetic Rehabilitation System. Group One received a single manipulation. Rotator cuff peak torque was measured pre-manipulation, immediately post manipulation and at a two-week follow up. Group Two received four manipulations over a two week period. Rotator cuff peak torque was measured pre and immediately post the first manipulation. A third rotator cuff peak torque measurement was taken two weeks after the first manipulation. Results: There was no statistically significant effect of a single or multiple manipulations on rotator cuff peak torque (abduction, adduction, internal rotation and external rotation). Inter-group analysis revealed a trend of an effect for abduction as the single manipulation increased at the two-week follow up and the multiple manipulation group decreased; however, this was not statistically significant. Conclusion: No statistically significant results were found possibly due to small sample size and the fact that objective measurements were only taken at the beginning and the end of the research processes and not at regular intervals throughout the study.Further studies are needed to determine the effects of multiple manipulations on peripheral muscle activity, including the treatment of symptomatic patients with rotator cuff pathology. It is also recommended that EMG readings be done in conjunction with peak torque measures to determine muscle activity.

The game of rugby union has evolved over the years into a professional sport in which an increased incidence of injury is evident. This also applies to the shoulder joint. It appears that certain risk factors are associated with shoulder pathology among rugby players as well as among the general population. In a competitive sporting environment where high stress loads are placed upon the body and joints, this association may be even more pronounced. Despite the fact that numerous studies have investigated the various factors that potentially play a role in the occurrence of shoulder injuries among sports participants generally, similar studies involving rugby union players in particular are limited. Previous studies have investigated and profiled rugby players with regards to posture, shoulder isokinetic muscle strength and electromyographic patterns, but no study has yet investigated the relationship between these factors and the role they may play in the risk of being injured. It would be beneficial to have a better understanding of the interplay between these factors and to identify the most likely factors to predict and/or prevent shoulder injuries in rugby players. With this information at hand, it might be possible to identify players who are at risk of shoulder injuries in order that they may potentially benefit from effective “pre-habilitation” protocols. The aim of this study was to determine what the relationship between thoracic posture, isokinetic shoulder strength and scapulae muscle activation patterns in injured and uninjured rugby players was, and to determine which of these variables might predict shoulder injuries. Methods Ninety-one (91) uninjured semi-professional rugby union players’ shoulder joint range of motion differences (ROM) were manually tested with the hand-behind-the-neck and hand- behind-the-back method. The profiling and classification of the thoracic posture was performed using the New York Posture Test. Scapular muscle activation patterns were determined by means of electromyography (EMG) measuring the activation of the upper and lower trapezius, serratus anterior and infrapinatus muscles. The isokinetic muscle strength of the rotator cuff muscles was determined at 60°/sec (Kin-Com 500H) measuring concentric and eccentric forces during internal and external rotation. Results Some participants presented with non-ideal or unsatisfactory shoulder internal rotators (59%) and external rotators (85%) bilateral ROM differences. Of all the participants, 68% presented with an abnormal shoulder position in the lateral view, and the sequence of muscle activation of the scapula stabiliser muscles was found to be: serratus anterior; lower trapezius; infraspinatus and then upper trapezius. The isokinetic antagonist/agonist strength ratio for shoulder rotation during concentric muscle contraction was 64% for the non-dominant and 54% for the dominant shoulder. The corresponding ratios for the eccentric muscle contraction of the non-dominant and dominant shoulders were 67% and 61% respectively. The median muscle onset times of the backline players’ non-dominant infraspinatus muscles were 35.90 ms for ideal, 95.20 ms for non-ideal, and 93.90 ms for the unsatisfactory external rotators’ range of motion (ROM) differences. The median firing orders of the forwards’ dominant lower trapezius muscle was 3 for ideal, 1 for non-ideal, and 2 for unsatisfactory external rotators’ ROM differences. Among the forward shoulder group and the normal shoulder position group of the forwards respectively, the median muscle onset time of their non-dominant infraspinatus muscle was 113 milliseconds (ms) and 42 ms. Their non- dominant serratus anterior muscles’ median onset time was 78.85 ms among the players with a rounded back, and 31.90 ms among the players with a normal thoracic curvature. The backline players displayed a median non-dominant serratus anterior onset time of 47.45 ms (in the uneven shoulder group) versus 32.75 ms (in the even shoulder group). The median firing order of the backline players’ non-dominant infraspinatus muscle was third in the normally curved back group. Among the players with an abnormally rounded back, however, the median firing order changed to second. The median external rotation/internal rotation isokinetic strength ratio of the forward players was 63% (forward shoulders), versus 56.50% (normal shoulder position). This was for their non-dominant shoulders. Certain isokinetic shoulder strength ratios displayed statistically significant correlations with scapular muscle activation patterns but they were not clinically significant. Players who had sustained shoulder injuries during the season differed significantly from those who had not sustained injuries with regards to the following baseline measurements: age (the injured were older), height (the injured were taller) and non-dominant/dominant concentric external rotation ratio (the injured had a higher ratio). Among the backline players baseline differences occurred within age (the injured were older), weight (the injured were heavier), height (the injured were taller) and the body mass index (BMI) (the injured had a higher BMI). The variables that displayed statistically significant predictive values towards future injury were age (1.34 times increase for each year older), insufficient shoulder external rotator ROM differences (16.15 times increase if an unsatisfactory ROM difference occurs), uneven shoulders (4.43 times increase if shoulders were abnormally uneven) and the non- dominant/dominant concentric external rotation strength ratio (a 1.42 times increase for every 10% that the ratio increases). Conclusion Profiling of the group of players revealed that their non-ideal or unsatisfactory flexibility of shoulder external rotators, their forward shoulders in the lateral view, and their weakness of the shoulder external rotators did not result in abnormal scapular muscle activation patterns. Positive relationships were found between certain postural abnormalities (forward shoulders, a rounded back and uneven shoulders) and the delay of muscle onset times of infraspinatus and serratus anterior, as well as the firing order of infraspinatus. Forward shoulders increased antagonist/agonist isokinetic shoulder rotation strength ratios. Non-ideal or unsatisfactory flexibility of shoulder external rotators displayed positive relationships with altered infraspinatus muscle onset times and an altered lower trapezius muscle firing order. No clinically significant correlations were found between isokinetic shoulder strength ratios and scapulae muscle activation patterns. It appears that posture (uneven shoulders), has a higher predictive ability than shoulder strength imbalance (non-dominant/dominant concentric external rotation ratio) regarding future shoulder injury. However, age and especially external rotator ROM deficiency proved to be strong predictors of future shoulder injury in semi-professional rugby players. / Thesis (PhD (Human Movement Science))--North-West University, Potchefstroom Campus, 2013.

The game of rugby union has evolved over the years into a professional sport in which an increased incidence of injury is evident. This also applies to the shoulder joint. It appears that certain risk factors are associated with shoulder pathology among rugby players as well as among the general population. In a competitive sporting environment where high stress loads are placed upon the body and joints, this association may be even more pronounced. Despite the fact that numerous studies have investigated the various factors that potentially play a role in the occurrence of shoulder injuries among sports participants generally, similar studies involving rugby union players in particular are limited. Previous studies have investigated and profiled rugby players with regards to posture, shoulder isokinetic muscle strength and electromyographic patterns, but no study has yet investigated the relationship between these factors and the role they may play in the risk of being injured. It would be beneficial to have a better understanding of the interplay between these factors and to identify the most likely factors to predict and/or prevent shoulder injuries in rugby players. With this information at hand, it might be possible to identify players who are at risk of shoulder injuries in order that they may potentially benefit from effective “pre-habilitation” protocols. The aim of this study was to determine what the relationship between thoracic posture, isokinetic shoulder strength and scapulae muscle activation patterns in injured and uninjured rugby players was, and to determine which of these variables might predict shoulder injuries. Methods Ninety-one (91) uninjured semi-professional rugby union players’ shoulder joint range of motion differences (ROM) were manually tested with the hand-behind-the-neck and hand- behind-the-back method. The profiling and classification of the thoracic posture was performed using the New York Posture Test. Scapular muscle activation patterns were determined by means of electromyography (EMG) measuring the activation of the upper and lower trapezius, serratus anterior and infrapinatus muscles. The isokinetic muscle strength of the rotator cuff muscles was determined at 60°/sec (Kin-Com 500H) measuring concentric and eccentric forces during internal and external rotation. Results Some participants presented with non-ideal or unsatisfactory shoulder internal rotators (59%) and external rotators (85%) bilateral ROM differences. Of all the participants, 68% presented with an abnormal shoulder position in the lateral view, and the sequence of muscle activation of the scapula stabiliser muscles was found to be: serratus anterior; lower trapezius; infraspinatus and then upper trapezius. The isokinetic antagonist/agonist strength ratio for shoulder rotation during concentric muscle contraction was 64% for the non-dominant and 54% for the dominant shoulder. The corresponding ratios for the eccentric muscle contraction of the non-dominant and dominant shoulders were 67% and 61% respectively. The median muscle onset times of the backline players’ non-dominant infraspinatus muscles were 35.90 ms for ideal, 95.20 ms for non-ideal, and 93.90 ms for the unsatisfactory external rotators’ range of motion (ROM) differences. The median firing orders of the forwards’ dominant lower trapezius muscle was 3 for ideal, 1 for non-ideal, and 2 for unsatisfactory external rotators’ ROM differences. Among the forward shoulder group and the normal shoulder position group of the forwards respectively, the median muscle onset time of their non-dominant infraspinatus muscle was 113 milliseconds (ms) and 42 ms. Their non- dominant serratus anterior muscles’ median onset time was 78.85 ms among the players with a rounded back, and 31.90 ms among the players with a normal thoracic curvature. The backline players displayed a median non-dominant serratus anterior onset time of 47.45 ms (in the uneven shoulder group) versus 32.75 ms (in the even shoulder group). The median firing order of the backline players’ non-dominant infraspinatus muscle was third in the normally curved back group. Among the players with an abnormally rounded back, however, the median firing order changed to second. The median external rotation/internal rotation isokinetic strength ratio of the forward players was 63% (forward shoulders), versus 56.50% (normal shoulder position). This was for their non-dominant shoulders. Certain isokinetic shoulder strength ratios displayed statistically significant correlations with scapular muscle activation patterns but they were not clinically significant. Players who had sustained shoulder injuries during the season differed significantly from those who had not sustained injuries with regards to the following baseline measurements: age (the injured were older), height (the injured were taller) and non-dominant/dominant concentric external rotation ratio (the injured had a higher ratio). Among the backline players baseline differences occurred within age (the injured were older), weight (the injured were heavier), height (the injured were taller) and the body mass index (BMI) (the injured had a higher BMI). The variables that displayed statistically significant predictive values towards future injury were age (1.34 times increase for each year older), insufficient shoulder external rotator ROM differences (16.15 times increase if an unsatisfactory ROM difference occurs), uneven shoulders (4.43 times increase if shoulders were abnormally uneven) and the non- dominant/dominant concentric external rotation strength ratio (a 1.42 times increase for every 10% that the ratio increases). Conclusion Profiling of the group of players revealed that their non-ideal or unsatisfactory flexibility of shoulder external rotators, their forward shoulders in the lateral view, and their weakness of the shoulder external rotators did not result in abnormal scapular muscle activation patterns. Positive relationships were found between certain postural abnormalities (forward shoulders, a rounded back and uneven shoulders) and the delay of muscle onset times of infraspinatus and serratus anterior, as well as the firing order of infraspinatus. Forward shoulders increased antagonist/agonist isokinetic shoulder rotation strength ratios. Non-ideal or unsatisfactory flexibility of shoulder external rotators displayed positive relationships with altered infraspinatus muscle onset times and an altered lower trapezius muscle firing order. No clinically significant correlations were found between isokinetic shoulder strength ratios and scapulae muscle activation patterns. It appears that posture (uneven shoulders), has a higher predictive ability than shoulder strength imbalance (non-dominant/dominant concentric external rotation ratio) regarding future shoulder injury. However, age and especially external rotator ROM deficiency proved to be strong predictors of future shoulder injury in semi-professional rugby players. / Thesis (PhD (Human Movement Science))--North-West University, Potchefstroom Campus, 2013.

Proprioceptive information appear to play an important role in stability and movements of shoulder joint in sporting activities especially in tennis. The purpose of this study was to measure the shoulder proprioceptive differences, and assess proprioceptive sense between dominant and non-dominant shoulders between male tennis players and controls between ages 14 - 16. 15 young male tennis players with a mean age 14.6 &plusmn / 0.7 years and 15 young male sedentary individuals with a mean age 14.8 &plusmn / 0.9 years participated in this cross-sectional descriptive study. Average height, weight, and BMI of the players were 169.4 &plusmn / 5.9 cm., 63.9 &plusmn / 5.5 kg., and 22.2 &plusmn / 1.0 kg/m2 respectively. Mean height, weight, and BMI of the non-players were 168.3 &plusmn / 5.3 cm., 64.4 &plusmn / 10.2 kg., and 23.1 &plusmn / 3.9 kg/m2 respectively. Proprioceptive sense was measured with an isokinetic dynamometer. Measurements were made in two positions: &lsquo / sitting&rsquo / versus &lsquo / standing&rsquo / for service, forehand, and backhand positions. Differences between players and control groups were investigated by MANOVA. Paired t-test was used to evaluate differences between dominant and non-dominant shoulders and sitting and standing positions. There was no statistically difference between players and non-players in means of age, body height, weight, and BMI. The study revealed the following results: 1) There was a significant difference between shoulder proprioceptive senses of players and controls (p &lt / 0.05) at service, forehand, and backhand positions. 2) Significant difference between dominant and non-dominant shoulders at 15&ordm / and 30&ordm / was not observed (p &lt / 0.05). 3) No significant difference was observed between sitting and standing positions at 30&ordm / (p &lt / 0.05). It was concluded that tennis players had better proprioceptive sense than their age matched sedentary controls.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. "This dissertation includes unpublished co-authored material"--P. v. Includes bibliographical references (leaves 119-128). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Thesis (M.S.)--Brock University, 2007. / Includes bibliographical references (leaves 79-84).

Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Thomas W. Kaminski, Dept. of Health, Nutrition, & Exercise Sciences. Includes bibliographical references.