Translations of the Humerus in Persons With Shoulder Impingement Symptoms

Abstract

Study Design: Two-group mixed-model analysis of covariance and correlation analysis. Objectives: To determine whether differences in humeral translations exist between patients with shoulder impingement symptoms and an asymptomatic comparison group, and if so, to determine if shoulder range-of-motion (ROM) measures are associated with abnormal translations. Background: Abnormal translations of the humeral head are believed to reduce the available subacromial space and to contribute to the development or progression of shoulder impingement symptoms. These abnormal translations have also been theorized to be related to tightness of the posterior capsule and decreased shoulder ROM. Methods and Measures: Three-dimensional humeral translations were tracked in symptomatic construction workers and an asymptomatic comparison group while elevating the arm in the scapular plane under no-load, 2.3-kg, and 4.6-kg hand-load conditions. Between-group comparisons were made across 3 phases of motion (30°-60°, 60°-90°, and 90°-120°) and the association between humeral translations and cross-body adduction and shoulder internal rotation ROM measures were determined by Pearson correlation analysis. Results: Persons with shoulder symptoms demonstrated small but significant changes in anterior-posterior translations of the humerus. These changes for the 90°-120°phase of humeral elevation were moderately negatively associated with available cross-body adduction ROM. Conclusions:The identified kinematic deviations are consistent with possible reductions of the subacromial space. Further study of relationships between posterior capsule tightness, rotator cuff function, and abnormal humeral translations is warranted to better delineate underlying kinematic mechanisms that may contribute to shoulder impingement symptoms and to refine rehabilitation techniques. J Orthop Sports Phys Ther 2002;32:248-259. Keywords: biomechanics, kinematics, shoulder motion abnormalitiesA bnormal kinematics of the shoulder have been associated with shoulder pathologies including impingement, instability, and rotator cuff tears. 27,39,40,63,67 It has been estimated that rotator cuff problems, including impingement and associated rotator cuff tendonitis and bursitis, account for nearly one-third of physician visits for shoulder pain complaints.42 If

Measuring dynamic in-vivo glenohumeral joint kinematics: Technique and preliminary results

“…3D imaging of glenohumeral joint position has been performed with MRI (Graichen et al 2000), CT (Baeyens et al 2001), or biplane radiography (Paletta et al 1997), but these techniques are currently limited to static analyses. Conventional motion measurement systems can track the position of surface markers or sensors during dynamic activities (Ludewig and Cook 2002), but these systems are susceptible to skin movement artifact and in-vivo accuracy assessment is difficult and rarely performed. Tracking of bone pins has also been used, but this invasive approach limits the number of willing volunteers and makes serial studies over time impractical .…”

Scapular Dysfunction in Throwers with Pathologic Internal Impingement

“…11 The elevation task is sensitive enough to show changes associated with shoulder pathology. 16,17 Additionally, our laboratory recently described the normal scapular movement patterns present in throwers using identical methodology. 27 Most lateral point on the lateral epicondyle Glenohumeral joint center (GH)* * The glenohumeral joint center was not palpated but, rather, estimated with a least-squares algorithm for the point on the humerus that moves the least during several short-arc humeral movements.…”

In vivo measurement of subacromial space width during shoulder elevation: Technique and preliminary results in patients following unilateral rotator cuff repair

“…These previous studies have measured the subacromial space under in-vivo conditions with various imaging modalities, including three-dimensional (3D) computed tomography (Lochmuller et al, 1997), clinical radiographs (van de Sande and Rozing, 2006,van de Sande et al, 2006,Lehtinen et al, 2000,Petersson and Redlund-Johnell, 1984, ultrasound imaging (Girometti et al, 2006,Azzoni et al, 2004, and MRI (Pappas et al, 2006,Graichen et al, 1998,Graichen et al, 1999b,Graichen et al, 1999a,Graichen et al, 2001,Graichen et al, 2005,Hinterwimmer et al, 2003,Roberts et al, 2002,Solem-Bertoft et al, 1993. Additional studies have estimated the subacromial space width based on shoulder kinematics as measured using skin-mounted sensors (Tsai et al, 2003,Thigpen et al, 2006,Ludewig and Cook, 2002,Nawoczenski et al, 2003. In addition, measurements of the subacromial space have also been recorded during operative procedures (Tillander and Norlin, 2002) and in various experiments using cadaveric shoulder specimens ,De Wilde et al, 2003,Flatow et al, 1994.…”