, which, in turn, results in nonfunctional kinematics. 6 – 8 Thus, it is necessary to evaluate both morphological and viscoelastic properties of shoulder girdle muscles during fatigue exercise. Overhead sports are also exposed to impingement, caused by both supraspinatus tendon thickness (SST) and
Sebastian Klich, Bogdan Pietraszewski, Matteo Zago, Manuela Galli, Nicola Lovecchio and Adam Kawczyński
Agnès Roby-Brami, Johanna V.G. Robertson, Alexandra Roren and Marie-Martine Lefèvre-Colau
This study explored the coordination between the components of the shoulder girdle (clavicle, scapula and humerus), and how they contribute to hand movement in the peri-personal space. Shoulder girdle motion was recorded in 10 healthy subjects during pointing movements to 9 targets in the peri-personal space, using electromagnetic sensors fixed to the trunk, scapula and upper arm. Most of the 9 degrees of freedom (DoF) of the shoulder girdle were finely scaled to target position. Principle component analysis revealed that the 6 DoF of scapula-thoracic motion were coordinated in three elementary patterns (protraction, shrug and lateral rotation). The ratio of gleno-humeral to scapulo-thoracic global motion was close to 2:1. A direct kinematic procedure showed that if no scapular motion occurred, the workspace would be reduced by 15.8 cm laterally, 13.7 cm vertically and 4.8 cm anteriorly. Scapulo-thoracic motion should be taken into account when investigating the physiology of upper-limb movements.
Harpa Helgadottir, Eythor Kristjansson, Sarah Mottram, Andrew Karduna and Halldor Jonsson Jr.
Clinical theory suggests that altered alignment of the shoulder girdle has the potential to create or sustain symptomatic mechanical dysfunction in the cervical and thoracic spine. The alignment of the shoulder girdle is described by two clavicle rotations, i.e, elevation and retraction, and by three scapular rotations, i.e., upward rotation, internal rotation, and anterior tilt. Elevation and retraction have until now been assessed only in patients with neck pain. The aim of the study was to determine whether there is a pattern of altered alignment of the shoulder girdle and the cervical and thoracic spine in patients with neck pain. A three-dimensional device measured clavicle and scapular orientation, and cervical and thoracic alignment in patients with insidious onset neck pain (IONP) and whiplash-associated disorder (WAD). An asymptomatic control group was selected for baseline measurements. The symptomatic groups revealed a significantly reduced clavicle retraction and scapular upward rotation as well as decreased cranial angle. A difference was found between the symptomatic groups on the left side, whereas the WAD group revealed an increased scapular anterior tilt and the IONP group a decreased clavicle elevation. These changes may be an important mechanism for maintenance and recurrence or exacerbation of symptoms in patients with neck pain.
Yaheli Bet-Or, Wolbert van den Hoorn, Venerina Johnston and Shaun O’Leary
Kinematics of the upper extremity are defined by relative movement of the clavicle, scapula, and humerus to the thorax. Accurate measurement of complex scapula motion during functional shoulder girdle activities is important in understanding normal human movement. 1 The acromion marker
Charles A. Thigpen and Darin A. Padua
Column-editor : Carl G. Mattacola
Samuele Contemori and Andrea Biscarini
Normal shoulder girdle functioning depends on the synchronous pattern of motion, commonly known as the scapulohumeral rhythm, between the glenohumeral (GH) and scapulothoracic (ST) joints. 1 This rhythm results from the coordinated activity of GH muscles (deltoid, supraspinatus, infraspinatus
Elif Turgut, Irem Duzgun and Gul Baltaci
. Interventions Self-stretching exercises were selected from frequently preferred exercises at the clinic, targeting the common soft tissue tightness around shoulder girdle. Selected exercises were pectoralis minor stretching 9 (Figure 1 ), posterior capsule stretching 16 (Figure 2 ), levator scapula
Suzanne LaScalza, Linda N. Gallo, James E. Carpenter and Richard E. Hughes
Clinical observation suggests that shoulder pathologies such as rotator cuff disorders and shoulder instability may alter the normal shoulder rhythm or relative motions of the structures comprising the shoulder girdle. The purpose of this study was to assess the accuracy of using a skin-mounted humeral cuff that could be used in vivo to determine Euler rotation angles and the helical axis of motion (HAM) during upper extremity movements. An in vitro model was used to compare the kinematics determined from the externally applied humeral cuff to the kinematics measured directly from the humerus. The upper extremities of five cadavers were moved through several humerus and forearm motion trials. Measurements from the humeral cuff were compared directly to the bone measurements for all trials to determine the accuracy of the Euler rotation angles. In evaluating the HAM, the orientation, location, and magnitude of rotation were compared either to the bone measurements or to the known rotational axis of the testing fixture. Euler rotation angles and the helical axis of motion determined by the measurements taken from the skin-mounted humeral cuff were very similar to those using the measurements from the bone-mounted sensor. The humeral cuff was shown to provide a viable, noninvasive method for determining the Euler rotation angles and helical axis of motion during 3-D humeral movements. The validation makes the humeral cuff a valuable tool for examining the effect of shoulder pathologies on the kinematics of the upper extremity.
Alison R. Valier, Ryan S. Averett, Barton E. Anderson and Cailee E. Welch Bacon
Shoulder pain is a common musculoskeletal complaint and is often associated with shoulder impingement. The annual incidence of shoulder pain is estimated to be 7% of all injuries, and is the third-most-common type of musculoskeletal pain. Initial treatment of shoulder impingement follows a conservative plan and emphasizes rehabilitation programs as opposed to surgical interventions. Shoulder rehabilitation programs commonly focus on strengthening the muscles of the shoulder complex and, more specifically, the rotator cuff. The rotator cuff is a primary dynamic stabilizer of the glenohumeral joint, using both eccentric and concentric contractions. The posterior rotator cuff, including teres minor and infraspinatus, works eccentrically to decelerate the arm during overhead throwing. Exercises to strengthen the rotator cuff and the surrounding dynamic stabilizers of the shoulder girdle vary and include activities such as internal and external rotation, full-can lifts, and rhythmic stabilizations. Traditionally, shoulder rehabilitation programs have focused on isotonic concentric contractions. Common strengthening exercises typically involve movements that result in shortening the muscle length while simultaneously loading the muscles. However, recent attention has been given to eccentric exercises, which involve lengthening of the muscle during loading, for the treatment of a variety of different tendinopathies including those of the Achilles and patellar tendons. The eccentric, or lengthening, motion is thought to be beneficial for people who are involved in activities that place eccentric stress on their shoulder, such as overhead throwers. Based on studies related to the Achilles tendon, eccentric exercise may positively influence the tendon structure by increasing collagen production and decreasing neovascularization. The changes that occur as a result of eccentric exercises may improve function, strength, and performance and decrease pain more than concentric programs, producing better patient outcomes. Although eccentric strength training has been shown to provide strength gains, there are no clear guidelines as to the inclusion of this form of exercise training in shoulder rehabilitation programs for the purposes of improving function and decreasing pain.
Focused Clinical Question:
Does adding an eccentric-exercise component to the rehabilitation program of patients with shoulder impingement improve shoulder function and/or decrease pain?
Razie J. Alibazi, Afsun Nodehi Moghadam, Ann M. Cools, Enayatollah Bakhshi and Alireza Aziz Ahari
workloads are considered risk factors for developing shoulder pain from inducing changes in shoulder girdle kinematics. 18 – 20 Most of the patients below 60 years of age who have shoulder impingement syndrome relate their symptoms to overhead work or sport activities. 21 They frequently elevate