PKI47I``refs.MYD||7@Bahk, M. Keyurapan, E. Tasaki, A. Sauers, E. L. McFarland, E. G.2007(Laxity testing of the shoulder: a review131-44Am J Sports Med351 2006/11/30Biomechanics Humans Joint Instability/*diagnosis/*physiopathology Physical Examination Range of Motion, Articular/physiology Shoulder Joint/*physiopathologyJan6Laxity testing is an important part of the examination of any joint. In the shoulder, it presents unique challenges because of the complexity of the interactions of the glenohumeral and scapulothoracic joints. Many practitioners believe that laxity testing of the shoulder is difficult, and they are unclear about its role in evaluation of patients. The objectives of the various laxity and instability tests differ, but the clinical signs of such tests can provide helpful information about joint stability. This article summarizes the principles of shoulder laxity testing, reviews techniques for measuring shoulder laxity, and evaluates the clinical usefulness of the shoulder laxity tests. Shoulder laxity evaluation can be a valuable element of the shoulder examination in patients with shoulder pain and instability.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17130247Bahk, Michael Keyurapan, Ekavit Tasaki, Atsushi Sauers, Eric L McFarland, Edward G Review United States The American journal of sports medicine Am J Sports Med. 2007 Jan;35(1):131-44. Epub 2006 Nov 27.0363-5465 (Print)17130247Division of Sports Medicine and Shoulder Surgery, Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, MD 21224-2780, USA. ehenze1@jhmi.edu./0363546506294570 [pii] 10.1177/0363546506294570enga||7Gannon, L. M. Bird, H. A.1999:The quantification of joint laxity in dancers and gymnasts743-50 J Sports Sci179 1999/10/16Adult Analysis of Variance Dancing/*physiology Female Gymnastics/*physiology Humans *Joint Instability Male Movement *Range of Motion, Articular Sex Factors Statistics, NonparametricSepmThe aim of this study was to determine the range of movement in gymnastic and dance populations. Sixty-five participants (41 females, 24 males; mean age 21.4 years) were assessed. The sample included dancers and gymnasts ranging from novice and club standard to international and professional status. Non-specialized physical education students acted as controls. Range of movement was measured at the shoulders, hips, lumbar spine and ankles using a Loebl hydrogoniometer, and inherent joint laxity was assessed using Beighton and coworkers' adaptation of the Carter and Wilkinson 9-point scale. The right and left sides of the body were assessed and measures of active and passive motion were recorded. A graded increase in laxity was observed from controls, through novice gymnasts, to dancers and finally international gymnasts. The greater laxity of females than males was also confirmed. Dancers and gymnasts had a greater passive range of movement in all joints, which was partly inherited and partly acquired. There was a large difference between their active and passive ranges, which appeared to render the joints unstable.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=10521005~Gannon, L M Bird, H A Research Support, Non-U.S. Gov't England Journal of sports sciences J Sports Sci. 1999 Sep;17(9):743-50.0264-0414 (Print)10521005School of Leisure and Sport Studies, Rheumatology and Rehabilitation Research Unit, Leeds Metropolitan University, UK. lgannon@lmu.ac.ukeng ||7Illyes, A. Kiss, R. M.2006mKinematic and muscle activity characteristics of multidirectional shoulder joint instability during elevation673-85#Knee Surg Sports Traumatol Arthrosc147 2005/12/20Adult Biomechanics Case-Control Studies Electromyography Female Humans Joint Instability/*physiopathology Male Movement/*physiology Muscle, Skeletal/*physiopathology Shoulder Joint/*physiopathologyJulAlterations of shoulder motion have been suggested to be associated with shoulder disorders. The objective of this study was to perform a 3D motion analysis (kinematic and electromyographical) of skeletal elements and muscles of shoulder joint in patients with multidirectional instability. Fifteen patients with multidirectional instability and 15 normal controls were investigated during continuous elevation in the scapular plane. The spatial coordinates of 16 anatomical points of the shoulder to determine kinematical parameters were quantified by an ultrasound-based motion analyzer. The activities of 12 muscles were measured by surface electromyography. Kinematic characteristics of motion were identified by scapulothoracic, glenohumeral, and humeral elevation angles; range of angles; scapulothoracic and glenohumeral rhythm; scapulothoracis, glenohumeral, and scapuloglenoid ratios; and the relative displacement between the rotation centers of the humerus and the scapula. The electromyographical characteristics of motion were modeled by the on-off pattern of muscle activity. Significant alterations in kinematical parameters were observed between patients and asymptomatic volunteers. The anterior, posterior, and inferior dislocations of shoulders with multidirectional instability could be properly modeled by the relative displacement between the rotation centers of the scapula and humerus. The shorter activity by m. pectoralis maior and all three parts of m. deltoideus and longer activity by m. supraspinatus, m. biceps brachii, and m. infraspinatus assure the centralization of the glenuhumeral head of a shoulder with multidirectional instability.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16362361Illyes, Arpad Kiss, Rita M Research Support, Non-U.S. Gov't Germany Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Knee Surg Sports Traumatol Arthrosc. 2006 Jul;14(7):673-85. Epub 2005 Dec 14.0942-2056 (Print)16362361WOrthopaedic Department, Semmelweis University, Karolina ut 27, 1113, Budapest, Hungary.10.1007/s00167-005-0012-7engb||7Sohl, P. Bowling, A.19909Injuries to dancers. Prevalence, treatment and prevention317-22 Sports Med95 1990/05/01*Dancing Female Humans Male Occupational Diseases/diagnosis/epidemiology/therapy Students *Wounds and Injuries/diagnosis/epidemiology/therapyMayStudies from the USA and UK indicate that the back, neck and shoulder and the lower limb (particularly the hip, knee, ankle and foot) are the most frequent sites of injury among dancers. Most injuries are soft tissue injuries. Most dancers experience injuries at some time and about half have chronic injuries. Shoulder injuries appear to be caused by frequent or unaccustomed lifting, and are treated by rest and oral anti-inflammatory medication. Back injuries include sprains, prolapsed or herniated intervertebral discs, and spondylolytic stress fractures. Several risk factors, especially training error, have been identified for overuse injuries. Hip injuries include degenerative changes and osteoarthritis, stress fractures, bursitis and damage to the sciatic nerve. The most common foot injury is an anterior lateral ligament sprain, which may lead to permanent instability in the ankle. More soundly based research into the prevalence, diagnosis and treatment of injuries is needed.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=2188333hSohl, P Bowling, A Review New zealand Sports medicine (Auckland, N.Z.) Sports Med. 1990 May;9(5):317-22.0112-1642 (Print)2188333`Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, England.eng ||7EWarner, J. J. Micheli, L. J. Arslanian, L. E. Kennedy, J. Kennedy, R.1990pPatterns of flexibility, laxity, and strength in normal shoulders and shoulders with instability and impingement366-75Am J Sports Med184 1990/07/01Adult Biomechanics Exertion/*physiology Female Humans Joint Instability/*physiopathology/rehabilitation Male Movement/*physiology *Muscle Contraction Shoulder/*physiology/physiopathology Shoulder Joint/physiology/*physiopathology SportsJul-Aug) Imbalance of the internal and external rotator musculature of the shoulder, excess capsular laxity, and loss of capsular flexibility, have all been implicated as etiologic factors in glenohumeral instability and impingement syndrome; however, these assertions are based largely on qualitative clinical observations. In order to quantitatively define the requirements of adequate protective synergy of the internal and external rotator musculature, as well as the primary capsulolabral restraints, we prospectively evaluated 53 subjects: 15 asymptomatic volunteers, 28 patients with glenohumeral instability, and 10 patients with impingement syndrome. Range of motion was evaluated by goniometric technique in all patients with glenohumeral instability and impingement. Laxity assessment was performed and anterior, posterior, and inferior humeral head translation was graded on a scale of 0 to 3+. Isokinetic strength assessment was performed in a modified abducted position using the Biodex Clinical Data Station with test speeds of 90 and 180 deg/sec. Internal and external rotator ratios and internal and external rotator strength deficits were calculated for both peak torque and total work. Patients with impingement demonstrated marked limitation of shoulder motion and minimal laxity on drawer testing. Both anterior and multidirectional instability patients had excessive external rotation as well as increased capsular laxity in all directions. Sixty-eight percent of the patients with instability had significant impingement signs in addition to apprehension and capsular laxity. Isokinetic testing of asymptomatic subjects demonstrated a 30% greater internal rotator strength in the dominant shoulder. Comparison of all three experimental groups demonstrated a significant difference between internal and external rotator ratios for both peak torque and total work. Conclusions are that there appears to be a dominance tendency with regard to internal rotator strength in asymptomatic individuals. Impingement syndrome and anterior instability have significant differences in both strength patterns of the rotator muscles and flexibility and laxity of the shoulder. Isokinetic testing potentially may be helpful in diagnostically differentiating between these two groups in cases where there is clinical overlap of signs and symptoms.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=2403184Warner, J J Micheli, L J Arslanian, L E Kennedy, J Kennedy, R Comparative Study United states The American journal of sports medicine Am J Sports Med. 1990 Jul-Aug;18(4):366-75.0363-5465 (Print)2403184`Division of Sports Medicine, Children's Hospital, Harvard Medical School, Boston, Massachusetts.eng 2||7+Ebaugh, D. D. McClure, P. W. Karduna, A. R.2006zEffects of shoulder muscle fatigue caused by repetitive overhead activities on scapulothoracic and glenohumeral kinematics224-35J Electromyogr Kinesiol163 2005/08/30Adolescent Adult Biomechanics/methods Exertion/*physiology Female Humans Humerus/physiology Male Muscle Contraction/*physiology Muscle Fatigue/*physiology Range of Motion, Articular/*physiology Scapula/physiology Shoulder Joint/*physiology Thorax/physiologyJundThe purpose of this study was to determine the effects of shoulder muscle fatigue on three dimensional scapulothoracic and glenohumeral kinematics. Twenty healthy subjects participated in this study. Three-dimensional scapulothoracic and glenohumeral kinematics were determined from electromagnetic sensors attached to the scapula, humerus, and thorax. Surface electromyographic (EMG) data were collected from the upper and lower trapezius, serratus anterior, anterior and posterior deltoid, and infraspinatus muscles. Median power frequency (MPF) values were derived from the raw EMG data and were used to indicate the degree of local muscle fatigue. Kinematic and EMG measures were collected prior to and immediately following the performance of a shoulder elevation fatigue protocol. Following the performance of the fatigue protocol subjects demonstrated more upward and external rotation of the scapula, more clavicular retraction, and less humeral external rotation during arm elevation. All muscles with the exception of the lower trapezius showed EMG signs of fatigue, the most notable being the infraspinatus and deltoid muscles. In general, greater scapulothoracic motion and less glenohumeral motion was observed following muscle fatigue. Further studies are needed to determine what effects these changes have on the soft tissues and mechanics of the shoulder complex.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16125416FEbaugh, D David McClure, Philip W Karduna, Andrew R R03 oh 3869/oh/niosh Clinical Trial Research Support, U.S. Gov't, P.H.S. England Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology J Electromyogr Kinesiol. 2006 Jun;16(3):224-35. Epub 2005 Aug 24.1050-6411 (Print)16125416Programs in Rehabilitation Sciences, Rehabilitation Sciences Biomechanics Lab, Drexel University, 245 North, 15th Street, MS 502, Philadelphia, PA 19102-1192, USA. debaugh@drexel.edu9S1050-6411(05)00080-5 [pii] 10.1016/j.jelekin.2005.06.015eng ||7+Ebaugh, D. D. McClure, P. W. Karduna, A. R.2005PThree-dimensional scapulothoracic motion during active and passive arm elevation700-9Clin Biomech (Bristol, Avon)207 2005/06/07FAdolescent Adult Arm/anatomy & histology/*physiology Electromyography Female Humans Image Interpretation, Computer-Assisted/methods Imaging, Three-Dimensional/methods Male Movement/*physiology Muscle Contraction/physiology Muscle, Skeletal/*physiology Rotation Scapula/*physiology Shoulder Joint/*physiology Thorax/*physiologyAug)BACKGROUND: Scapulothoracic muscle activity is believed to be important for normal scapulothoracic motion. In particular, the trapezius and serratus anterior muscles are believed to play an important role in the production and control of scapulothoracic motion. The aim of this study was to determine the effects of different levels of muscle activity (active versus passive arm elevation) on three-dimensional scapulothoracic motion. METHODS: Twenty subjects without a history of shoulder pathology participated in this study. Three-dimensional scapulothoracic motion was determined from electromagnetic sensors attached to the scapula, thorax and humerus during active and passive arm elevation. Muscle activity was recorded from surface electrodes over the upper and lower trapezius, serratus anterior, anterior and posterior deltoid, and infraspinatus muscles. Differences in scapulothoracic motion were calculated between active and passive arm elevation conditions. FINDINGS: Scapular motion was observed during the trials of passive arm elevation; however, there was more upward rotation of the scapula, external rotation of the scapula, clavicular retraction, and clavicular elevation under the condition of active arm elevation. This was most pronounced for scapular upward rotation through the mid-range (90-120 degrees) of arm elevation. INTERPRETATION: The upper and lower trapezius and serratus anterior muscles have an important role in producing upward rotation of the scapula especially throughout the mid-range of arm elevation. Additionally, it appears that capsuloligamentous and passive muscle tension contribute to scapulothoracic motion during arm elevation. Assessment of the upper and lower trapezius and serratus anterior muscles and upward rotation of the scapula should be part of any shoulder examination.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15935534Ebaugh, D David McClure, Philip W Karduna, Andrew R R03-oh038869/oh/niosh Clinical Trial Research Support, N.I.H., Extramural Research Support, U.S. Gov't, P.H.S. England Clinical biomechanics (Bristol, Avon) Clin Biomech (Bristol, Avon). 2005 Aug;20(7):700-9.0268-0033 (Print)15935534Rehabilitation Sciences Biomechanics Laboratory, Drexel University, 245 North 15th Street MS 502, Philadelphia, PA 19102-1192, USA. debaugh@drexel.edu=S0268-0033(05)00077-X [pii] 10.1016/j.clinbiomech.2005.03.008eng /||7Ogston, J. B. Ludewig, P. M.2007|Differences in 3-dimensional shoulder kinematics between persons with multidirectional instability and asymptomatic controls1361-70Am J Sports Med358 2007/04/11AugzBACKGROUND: Evidence that persons with multidirectional instability (MDI) of the shoulder have abnormal shoulder kinematics is limited. A kinematic description of scapulothoracic and glenohumeral motion can assist both conservative and surgical rehabilitative programs. HYPOTHESIS: Persons with MDI of the shoulder demonstrate increased anterior and inferior glenohumeral translation and decreased scapular upward rotation and increased scapular internal rotation compared with age-matched and gender-matched asymptomatic controls. STUDY DESIGN: Controlled laboratory study. METHODS: Sixty-two subjects were recruited from an outpatient orthopaedic clinic. Subjects with MDI were matched according to age, gender, and hand dominance to asymptomatic controls. An electromagnetic motion capture system evaluated the 3-dimensional position of the trunk, scapula, and humerus during frontal and scapular plane elevation. A repeated measures analysis of variance evaluated joint positions and glenohumeral translations during 4 phases of elevation (0 degrees-30 degrees, 31 degrees-60 degrees, 61 degrees-90 degrees, and 91 degrees-120 degrees). RESULTS: When averaged across the 4 phases of elevation, persons with MDI demonstrated a significant decrease in scapular upward rotation in scapular plane abduction (8 degrees, P = .006) and abduction (5.8 degrees, P = .016) and increased internal rotation during scapular plane abduction (12.2 degrees, P = .03). Alterations in glenohumeral translations in the MDI group did not reach statistical significance (P = .54-.71). CONCLUSION: Abnormal scapular kinematics are seen in the MDI shoulder, highlighting the importance of incorporating scapular positioning and stability exercises during rehabilitation. Additional study is warranted concerning the efficacy of various rehabilitation programs, and also both surgical and nonsurgical interventions in this population.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17420507Ogston, Jena B Ludewig, Paula M Research Support, Non-U.S. Gov't United States The American journal of sports medicine Am J Sports Med. 2007 Aug;35(8):1361-70. Epub 2007 Apr 9.0363-5465 (Print)17420507UCollege of St. Scholastica, 1200 Kenwood Ave., Duluth, MN 55811, USA. jogston@css.edu/0363546507300820 [pii] 10.1177/0363546507300820eng }|7 Mvon Eisenhart-Rothe, R. Matsen, F. A., 3rd Eckstein, F. Vogl, T. Graichen, H.2005nPathomechanics in atraumatic shoulder instability: scapular positioning correlates with humeral head centering82-9Clin Orthop Relat Res433 2005/04/05jAdolescent Adult Biomechanics Case-Control Studies Female Humans *Image Processing, Computer-Assisted Joint Instability/*diagnosis Magnetic Resonance Imaging Male Middle Aged Range of Motion, Articular/*physiology Reference Values Sensitivity and Specificity Severity of Illness Index Shoulder Dislocation/*diagnosis Shoulder Joint/anatomy & histology/physiologyAprThe objective was to analyze three-dimensional scapular positioning and glenohumeral centering of normal and atraumatic unstable shoulders. We hypothesized that changes of humeral head position correlate with alterations of scapular positioning. The shoulders of 28 healthy volunteers and 14 patients with atraumatic instability were examined in various arm positions using open magnetic resonance imaging. After segmentation and three-dimensional reconstruction, three-dimensional analyses of scapular positioning and humeral head position relative to the glenoid were done. The coefficient of correlation (r) between both parameters was determined using the correlation z test. The glenohumeral to scapulothoracic ratio in the scapular plane was increased in nine of 14 patients and decreased in three patients, whereas the scapular internal rotation in the transverse plane was increased in all unstable shoulders. The unstable shoulders also had malcentering (greater than two times the standard deviation in the healthy volunteers) of the humeral head in the direction of instability during various arm positions. In healthy and unstable shoulders, the correlation between scapular position and glenohumeral positioning was high during passive elevation (r = 0.60-0.87). The high correlation suggests that scapular positioning is relevant for humeral head decentering. Therefore, physiotherapeutic strategy should consider the malpositioning of the scapula and be adapted to the direction of instability.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15805941von Eisenhart-Rothe, R Matsen, F A 3rd Eckstein, F Vogl, T Graichen, H Comparative Study Research Support, Non-U.S. Gov't United States Clinical orthopaedics and related research Clin Orthop Relat Res. 2005 Apr;(433):82-9.0009-921X (Print)15805941Research Group for Kinematics and Biomechanics, Department of Orthopedic Surgery, University of Frankfurt, Marienburgstrasse 2, 60528 Frankfurt, Germany. r_veisenhart@yahoo.de00003086-200504000-00013 [pii]eng||7 8Turkel, S. J. Panio, M. W. Marshall, J. L. Girgis, F. G.1981PStabilizing mechanisms preventing anterior dislocation of the glenohumeral joint1208-17J Bone Joint Surg Am638 1981/10/01Biomechanics Dissection Humans Ligaments, Articular/anatomy & histology/physiology/surgery Muscles/anatomy & histology/physiology/surgery Shoulder Dislocation/*prevention & control Shoulder Joint/*anatomy & histology/physiology/surgeryOctWe investigated the stabilizing mechanism of the glenohumeral joint that prevents anterior dislocation by anatomical dissections of the subscapularis, the shoulder capsule, and the superior, middle, and inferior glenohumeral ligaments in thirty-six shoulders of embalmed cadavera. We also performed roentgenographic studies of ten unembalmed cadaver shoulders in which radiopaque markers were used to demonstrate the position, tightness, and laxity of the subscapularis muscle and of the middle and inferior glenohumeral ligaments during external rotation of the shoulder at zero, 45, and 90 degrees of abduction. The subscapularis muscle and the three glenohumeral ligaments were cut in different sequences to determine their relative contributions to stability (limitation of external rotation). The conclusions from these experiments were that at zero degrees of abduction, the subscapularis muscle stabilizes the joint to a large extent; at 45 degrees of abduction, the subscapularis, middle glenohumeral ligament, and anterosuperior fibers of the inferior glenohumeral ligament provide the stability; and as the shoulder approaches 90 degrees of abduction, the inferior glenohumeral ligament prevents dislocation during external rotation.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=7287791Turkel, S J Panio, M W Marshall, J L Girgis, F G United states The Journal of bone and joint surgery. American volume J Bone Joint Surg Am. 1981 Oct;63(8):1208-17.0021-9355 (Print)7287791eng*||7 1Cain, P. R. Mutschler, T. A. Fu, F. H. Lee, S. K.1987=Anterior stability of the glenohumeral joint. A dynamic model144-8Am J Sports Med152 1987/03/01Humans Ligaments, Articular/physiology Models, Biological Muscles/physiology Rotation Shoulder Joint/*physiology Stress, MechanicalMar-AprThis study defines the interaction of the rotator cuff musculature and the glenohumeral ligaments in providing anterior stability to the glenohumeral joint. Eight cadaveric shoulders were studied using a testing frame that individually simulated the forces of the subscapularis, the supraspinatus, and the infraspinatus/teres minor musculature. The application of these forces abducted the humerus to approximately 90 degrees. The cocking phase of throwing was then simulated through the use of an Instron. With random variation of the rotator cuff forces, we investigated the effects that each force had on the rotation of the humerus and the strain of the inferior glenohumeral ligament. Our results demonstrate that the infraspinatus/teres minor muscle group was the most effective in controlling external rotation of the humerus and in reducing ligamentous strain. These observations are pertinent in the treatment of anterior instability syndromes of the shoulder.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=3578636Cain, P R Mutschler, T A Fu, F H Lee, S K United states The American journal of sports medicine Am J Sports Med. 1987 Mar-Apr;15(2):144-8.0363-5465 (Print)3578636eng||7 &Rodosky, M. W. Harner, C. D. Fu, F. H.1994pThe role of the long head of the biceps muscle and superior glenoid labrum in anterior stability of the shoulder121-30Am J Sports Med221 1994/01/01Elasticity Electromyography Humans Humerus/physiology Joint Instability/physiopathology Ligaments, Articular/physiology Male Middle Aged Movement Muscle Contraction/physiology Muscles/injuries/*physiology/physiopathology Potentiometry Rotation Rotator Cuff/physiology Shoulder Joint/injuries/*physiology/physiopathology Stress, Mechanical Tendon Injuries Tendons/*physiology/physiopathologyJan-FebThe authors conducted a study to determine if the long head of the biceps muscle and its attachment at the superior glenoid labrum play a role in stability of the shoulder in an overhead position. Their study used a dynamic cadaveric shoulder model that simulated the forces of the rotator cuff and long head of biceps muscles as the glenohumeral joint was abducted and externally rotated. Their data suggest that the long head of the biceps muscle contributes to anterior stability of the glenohumeral joint by increasing the shoulder's resistance to torsional forces in the vulnerable abducted and externally rotated position. The biceps muscle also helps to diminish the stress placed on the inferior glenohumeral ligament. Detachment of the superior glenoid labrum is detrimental to anterior shoulder stability as it decreases the shoulder's resistance to torsion and places a greater magnitude of strain on the inferior glenohumeral ligament.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8129095Rodosky, M W Harner, C D Fu, F H Research Support, Non-U.S. Gov't United states The American journal of sports medicine Am J Sports Med. 1994 Jan-Feb;22(1):121-30.0363-5465 (Print)8129095Albert B. Ferguson, Jr., M.D., Laboratory for Orthopaedic Research, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pennsylvania.eng &||7 PMyers, J. B. Ju, Y. Y. Hwang, J. H. McMahon, P. J. Rodosky, M. W. Lephart, S. M.2004[Reflexive muscle activation alterations in shoulders with anterior glenohumeral instability1013-21Am J Sports Med324 2004/05/20Adult Electromyography Humans Joint Instability/*physiopathology Muscle, Skeletal/*physiopathology Proprioception/*physiology Recurrence Rotator Cuff/physiopathology Shoulder Joint/*physiopathologyJunIBACKGROUND: Patients with glenohumeral instability have proprioceptive deficits that are suggested to contribute to muscle activation alterations. HYPOTHESIS: Muscle activation alterations will be present in shoulders with anterior glenohumeral instability. STUDY DESIGN: Posttest-only control group design. METHODS: Eleven patients diagnosed with anterior glenohumeral instability were matched with 11 control subjects. Each subject received an external humeral rotation apprehension perturbation while reflexive muscle activation characteristics were measured with indwelling electromyography and surface electromyography. RESULTS: Patients with instability demonstrated suppressed pectoralis major and biceps brachii mean activation; increased peak activation of the subscapularis, supraspinatus, and infraspinatus; and a significantly slower biceps brachii reflex latency. Supraspinatus-subscapularis coactivation was significantly suppressed in the patients with instability as well. CONCLUSIONS AND CLINICAL RELEVANCE: In addition to the capsuloligamentous deficiency and proprioceptive deficits present in anterior glenohumeral instability, muscle activation alterations are also present. The suppressed rotator cuff coactivation, slower biceps brachii activation, and decreased pectoralis major and biceps brachii mean activation may contribute to the recurrent instability episodes seen in this patient group. Clinicians can implement therapeutic exercises that address the suppressed muscles in patients opting for conservative management or rehabilitation before and after capsulorraphy procedures.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15150051Myers, Joseph B Ju, Yan-Ying Hwang, Ji-Hye McMahon, Patrick J Rodosky, Mark W Lephart, Scott M Research Support, Non-U.S. Gov't United States The American journal of sports medicine Am J Sports Med. 2004 Jun;32(4):1013-21.0363-5465 (Print)15150051Neuromuscular Research Laboratory, UPMC Center for Sports Medicine, University of Pittsburgh, 3200 South Water Street, Pittsburgh, PA 15203, USA. myersjb@msx.upmc.edueng||73Malanga, G. A. Jenp, Y. N. Growney, E. S. An, K. N.1996SEMG analysis of shoulder positioning in testing and strengthening the supraspinatus661-4Med Sci Sports Exerc286 1996/06/01|Adult Electromyography Exercise Female Humans Male Muscle, Skeletal/*physiology Rotator Cuff/physiology Shoulder/*physiologyJunWe examined the electromyographic (EMG) activity of the supraspinatus and other rotator cuff muscles, the three portions of the deltoid muscle, and the pectoralis major muscle in two previously suggested positions for isolating the supraspinatus. The position suggested by Jobe and colleagues is with the elbow extended, the shoulder in full internal rotation, and the arm in the scapular plane. Blackburn and colleagues recommended the prone position, with the elbow extended and the arm abducted to 100 degrees and externally rotated. Fine-wire EMG activity was obtained from the rotator cuff muscles and surface EMG from the other muscles in 17 subjects tested in these two positions. Both positions resulted in significant activity of the supraspinatus, but the difference between these two positions was not statistically significant. The Jobe position produced greater activation of the anterior deltoid and pectoralis major, whereas the Blackburn position caused greater activation of the posterior deltoid. Both positions produced significant activation of the middle deltoid. We conclude that either position can be used to strengthen the supraspinatus; however, neither position selectively isolates the supraspinatus during manual muscle testing.dhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8784752Malanga, G A Jenp, Y N Growney, E S An, K N United states Medicine and science in sports and exercise Med Sci Sports Exerc. 1996 Jun;28(6):661-4.0195-9131 (Print)8784752ZDepartment of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA.eng ||7Reinold, M. M. Wilk, K. E. Fleisig, G. S. Zheng, N. Barrentine, S. W. Chmielewski, T. Cody, R. C. Jameson, G. G. Andrews, J. R.2004yElectromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises385-94J Orthop Sports Phys Ther347 2004/08/07Adult Electromyography *Exercise Therapy Female Humans Isometric Contraction/physiology Male Muscle, Skeletal/*physiology Posture/physiology Prospective Studies *Rotation Rotator Cuff/*physiology Shoulder Joint/physiologyJuliSTUDY DESIGN: Prospective single-group repeated-measures design. OBJECTIVES: To quantify electromyographic (EMG) muscle activity of the infraspinatus, teres minor, supraspinatus, posterior deltoid, and middle deltoid during exercises commonly used to strengthen the shoulder external rotators. BACKGROUND: Exercises to strengthen the external rotators are commonly prescribed in rehabilitation, but the amount of EMG activity of the infraspinatus, teres minor, supraspinatus, and deltoid during these exercises has not been thoroughly studied to determine which exercises would be most effective to achieve strength gains. METHODS AND MEASURES: EMG measured using intramuscular electrodes were analyzed in 10 healthy subjects during 7 shoulder exercises: prone horizontal abduction at 100 degrees of abduction and full external rotation (ER), prone ER at 90 degrees of abduction, standing ER at 90 degrees of abduction, standing ER in the scapular plane (45 degrees abduction, 30 degrees horizontal adduction), standing ER at 0 degrees of abduction, standing ER at 0 degrees of abduction with a towel roll, and sidelying ER at 0 degrees of abduction. The peak percentage of maximal voluntary isometric contraction (MVIC) for each muscle was compared among exercises using a 1-way repeated-measures analysis of variance (P<.05). RESULTS: EMG activity varied significantly among the 7 exercises. Sidelying ER produced the greatest amount of EMG activity for the infraspinatus (62% MVIC) and teres minor (67% MVIC). The greatest amount of activity of the supraspinatus (82% MVIC), middle deltoid (87% MVIC), and posterior deltoid (88% MVIC) was observed during prone horizontal abduction at 100 degrees with full ER. CONCLUSIONS: Results from this study provide initial information to develop rehabilitation programs. It also provides information helpful for the design and conduct of future studies.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15296366 Reinold, Michael M Wilk, Kevin E Fleisig, Glenn S Zheng, Nigel Barrentine, Steven W Chmielewski, Terri Cody, Rayden C Jameson, Gene G Andrews, James R United States The Journal of orthopaedic and sports physical therapy J Orthop Sports Phys Ther. 2004 Jul;34(7):385-94.0190-6011 (Print)15296366zHealthsouth Rehabilitation, American Sports Medicine Institute, Birmingham, AL 35205, USA. michael.reinold@healthsouth.comeng u||7Johnson, G. R. Pandyan, A. D.2005{The activity in the three regions of the trapezius under controlled loading conditions--an experimental and modelling study155-61Clin Biomech (Bristol, Avon)202 2004/12/29%Adult Computer Simulation Diagnosis, Computer-Assisted/*methods Electromyography/*methods Humans Isometric Contraction/*physiology Male *Models, Biological Muscle, Skeletal/*physiology Physical Stimulation/methods Shoulder Joint/*physiology Stress, Mechanical Torque Weight-Bearing/*physiologyFebBACKGROUND: There is a degree of conflict in the literature regarding the biomechanical role of the three regions of trapezius. It is suggested that some of this may result from a lack of experiments using a well defined loading regime. OBJECTIVES: To study the activity of the three regions of trapezius under controlled load in order to gain further insight into its role in shoulder biomechanics. DESIGN: The emg activity of the three regions of trapezius was studied on five subjects using a specially designed test system which allowed the application of either a uniaxial shrug force or a pure couple in the coronal plane. METHODS: Test rigs were designed and constructed to measure isometric loads applied by shoulder shrugging and isometric pure moments produced in coronal plane abduction and adduction. Surface emg of the three regions of trapezius was performed simultaneously with loading. RESULTS: The activity of upper trapezius was always present but changed little with the type of loading. Middle trapezius was dominant during both shrug and abduction whereas the lower fibres predominated during adduction. CONCLUSIONS: The use of a test system applying defined loading at the shoulder allows the detail analysis of trapezius muscle activity. The reproducible technique can be extended to other shoulder muscles. RELEVANCE: The biomechanics of the shoulder calls for detailed analysis of the activity of all the interacting muscles. This paper describes a techniques which allows study of muscle activity under carefully defined loading.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15621319Johnson, Garth R Pandyan, Anand D Clinical Trial Comparative Study Research Support, Non-U.S. Gov't Validation Studies England Clinical biomechanics (Bristol, Avon) Clin Biomech (Bristol, Avon). 2005 Feb;20(2):155-61.0268-0033 (Print)15621319Centre for Rehabilitation and Engineering Studies, Stephenson Building, University of Newcastle, Newcastle Upon Tyne NE1 7RU, UK. g.r.johnson@ncl.ac.uk=S0268-0033(04)00244-X [pii] 10.1016/j.clinbiomech.2004.10.005eng ||70Ekstrom, R. A. Donatelli, R. A. Soderberg, G. L.2003_Surface electromyographic analysis of exercises for the trapezius and serratus anterior muscles247-58J Orthop Sports Phys Ther335 2003/05/31Adult Electromyography Exercise Therapy/*methods Female Humans Male Middle Aged Movement/physiology Muscle, Skeletal/*physiology Prospective Studies Reproducibility of Results Shoulder/*physiologyMayJSTUDY DESIGN: This study used a prospective, single-group repeated-measures design to analyze differences between the electromyographic (EMG) amplitudes produced by exercises for the trapezius and serratus anterior muscles. OBJECTIVE: To identify high-intensity exercises that elicit the greatest level of EMG activity in the trapezius and serratus anterior muscles. BACKGROUND: The trapezius and serratus anterior muscles are considered to be the only upward rotators of the scapula and are important for normal shoulder function. Electromyographic studies have been performed for these muscles during active and low-intensity exercises, but they have not been analyzed during high intensity exercises. METHODS AND MEASURES: Surface electrodes recorded EMG activity of the upper, middle, and lower trapezius and serratus anterior muscles during 10 exercises in 30 healthy subjects. RESULTS: The unilateral shoulder shrug exercise was found to produce the greatest EMG activity in the upper trapezius. For the middle trapezius, the greatest EMG amplitudes were generated with 2 exercises: shoulder horizontal extension with external rotation and the overhead arm raise in line with the lower trapezius muscle in the prone position. The arm raise overhead exercise in the prone position produced the maximum EMG activity in the lower trapezius. The serratus anterior was activated maximally with exercises requiring a great amount of upward rotation of the scapula. The exercises were shoulder abduction in the plane of the scapula above 120 degrees and a diagonal exercise with a combination of shoulder flexion, horizontal flexion, and external rotation. CONCLUSION: This study identified exercises that maximally activate the trapezius and serratus anterior muscles. This information may be helpful for clinicians in developing exercise programs for these muscles.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12774999Ekstrom, Richard A Donatelli, Robert A Soderberg, Gary L Clinical Trial United States The Journal of orthopaedic and sports physical therapy J Orthop Sports Phys Ther. 2003 May;33(5):247-58.0190-6011 (Print)12774999SRocky Mountain University of Health Professions, Provo, Utah, USA. rekstrom@usd.edueng ||7[Lister, J. L. Del Rossi, G. Ma, F. Stoutenberg, M. Adams, J. B. Tobkin, S. Signorile, J. F.2007OScapular stabilizer activity during Bodyblade, cuff weights, and Thera-Band use50-67J Sport Rehabil161 2007/08/21Feb]CONTEXT: There are numerous ways to overload the scapular stabilizers. OBJECTIVES: To assess scapular stabilizer activity using the Bodyblade and other traditional training devices. DESIGN: Repeated measures analysis of surface EMG data collected from the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) during shoulder flexion and abduction using Bodyblade, cuff weight, and Thera-Band resistance. SETTING: Laboratory. PARTICIPANTS: Thirty collegiate athletes (20.0 +/- 1.7 years). INTERVENTION: Participants performed 10 repetitions of shoulder flexion and abduction. MAIN OUTCOME MEASURES: For each movement, normalized root mean square values (NrmsEMG) were computed for each muscle during each repetition under each training condition. Data were analyzed using 3 (condition) 3 10 (repetition) repeated measures ANOVAs. RESULTS: During shoulder flexion and abduction, the NrmsEMG of the UT, LT, and SA were significantly greater when using the Bodyblade than the Thera-Band or cuff weight. CONCLUSION: The Bodyblade produces greater scapular activity than traditional resistance techniques.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17699887Lister, Jennifer L Del Rossi, Gianluca Ma, Fangchao Stoutenberg, Mark Adams, Jessica B Tobkin, Sara Signorile, Joseph F United States Journal of sport rehabilitation J Sport Rehabil. 2007 Feb;16(1):50-67.1056-6716 (Print)17699887VDept of Exercise and Sport Sciences at the University of Miami, Coral Gables, FL, USA.eng1||7@Partin, N. B. Stone, J. A. Ryan, E. J. Lueken, J. S. Timm, K. E.1994'Upper Extremity Proprioceptive Training15-18 J Athl Train291 1994/03/01MarProprioception following lower extremity injuries is commonly recommended, but there is little information on proprioception training following upper extremity injuries. No studies have evaluated whether proprioception programs for athletes in open kinetic chain activities (throwing, shot putting) should be different than programs for athletes in closed kinetic chain activities (gymnastics, swimming, kayaking, or rowing). In this paper, we provide a rationale for proprioception training for upper extremity injuries in athletes and the importance of analyzing the athlete's sport and activity for specificity of proprioception exercises. We then discuss one popular proprioception exercise, rhythmic stabilization, and propose several additional upper extremity proprioception exercises, along with instructions for the athletic trainer on how to direct the athlete through these exercises.ehttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=165582543Journal article J Athl Train. 1994 Mar;29(1):15-18.1062-6050 (Print)165582547Nina B. Partin is Athletic Trainer in Nacogdoches, Tex.EngPKF47I/**refs.FRM 0B< !// !HPRIMARYyearIndex 6ByP/) idreference_type text_stylesauthoryear title pages secondary_title volume numbernumber_of_volumessecondary_authorplace_published publishersubsidiary_authoredition keywords type_of_workdate2)  abstractlabelurltertiary_titletertiary_author notes isbn custom_1 custom_2 custom_3 custom_4alternate_titleaccession_number call_number short_title custom_5 custom_6sectionoriginal_publicationH) reprint_editionreviewed_itemauthor_addressimagecaption custom_7 electronic_resource_number link_to_pdf translated_author translated_titlename_of_databasedatabase_providerresearch_notes language access_datelast_modified_date !! H!H!H! (H! 3H! >H! IH! TH!_H!jH!uH! H!H!H! H! H!H! H!H!H!H!H! H! H! H! H! %H! 0H!;H!FH! QH! \H! gH! rH!}H!H!H!H!H!H!H! H! H! H! H! H!H! H!H! 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