June 6, 2023

Glenohumeral Osteoarthritis and Frozen Shoulder Alters Scapular Kinematics

Learn about the effects of Glenohumeral Osteoarthritis and Frozen Shoulder on Scapular Kinematics. Understand how these conditions affect mobility and function.

Brent Brookbush

DPT, PT, MS, CPT, HMS, IMT

Research Review: Glenohumeral Osteoarthritis and Frozen Shoulder Alters Scapular Kinematics

By Lynn Willford PT, MS, Cert MDT

Edited by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

Original Citation: Fayad F, Roby-Brami A, Yazbeck C, Hanneton S, Lefevre-Colau MM, Gautheron V, Poiraudeau S, Revel M. (2008). "Three-dimensional scapular kinematics and scapulohumeral rhythm in patients with glenohumeral osteoarthritis or frozen shoulder." 2008 Jbiomech, 41(2): 326-332 - ABSTRACT

Frozen Shoulder (Adhesive Capsulitis) - http://s3.amazonaws.com/readers/2010/08/23/frozen-shoulder-syndrome_1.jpg

Why is this relevant?: Shoulder pain is one of the most common reasons an individual seeks advice from a human movement professional. Two particularly persistent conditions are frozen shoulder (FS) and glenohumeral (GH) osteoarthritis. The clinical presentation of these disorders are similar, both typically presenting with pain and limited joint mobility in individuals 40 year of age or older. Interestingly, based on this study the scapular dyskinesis associated with these disorders is similar to other GH pathologies (impingement syndrome), and exactly what a human movement professional might expect. Having a firm understanding of the mechanical presentation and kinematics of the shoulder and scapula will lead to better management of these issues, refine exercise and technique selection, and result in better outcomes.

Study Summary

Study Design	Non-experimental Comparative Study
Level of Evidence	Level VI : Evidence from a single descriptive or qualitative study
Subject Demographics	Age: Glenohumeral Osteoarthritis Group (GH) = 72.4 +/-8.7 yrs ; Frozen Shoulder Group (FS) = 48.8 +/- 6.7yrs Gender: 25 Female (13 GH;12 FS); 7 Male (2 GH; 3 FS) Characteristics: Affected side Right (9 GH; 10 FS); Affected side Left (2 GH; 6 FS); Bilateral (5 GH; ) FS) Duration of symptoms (mean) 58.6 months GH; 11.9 months FS Pain Visual Analog Scale (VAS) 0 -100 (mean) at rest: 25.9 GH; 14.2 FS with activity: 66.1 GH; 52.5 FS Maximal humeral elevation (mean) Frontal plane - 90.6 GH; 66.4 FS Sagittal plane - 103 GH; 88.8 FS Inclusion Criteria: diagnosis of either GH osteoarthritis or frozen shoulder. The diagnosis of GH osteoarthritis was based on plain x-ray showing a narrowing of the GH space. The diagnosis of FS was defined as a pattern of limited joint mobility with normal plain x-rays. Exclusion Criteria: cervical radiculopathy, history of cervico-thoracic outlet compression syndrome, rheumatic disease or shoulder trauma
Outcome Measures	The measurements were gathered using an electromagnetic tracking device, the Polhemus Fastrak (SPACE FASTRAK, Colchester, VT). The transmitter was fitted on a rigid plastic frame in front of the subject. Three sensors were adhered to the subject on their sternum, the superior acromion process, and the lateral arm just below the insertion of the deltoid. The Fourth sensor was mounted on a pointer that manually digitized nine bony landmarks on the thorax, scapula and humerus. maximal active arm elevation in the sagittal and frontal planes of the affected side value of scapular protraction/retraction at humeral angles of 30, 45, 60 degrees and maximal elevation value of scapular lateral/medial rotation at humeral angles of 30, 45, 60 degrees and maximal elevation value of scapular anterior/posterior tilt aT humeral angles of 30, 45, 60 degrees and maximal elevation value of scapular rotations of the unaffected side were calculated at a "reference" level corresponding with the maximal elevation of the contralateral affected side Ratio of scapular upward rotation to humeral elevation, scapulohumeral rhythm (SHR) was calculated at the maximal elevation of the affected side and at the "reference" position for the unaffected side in both the frontal and sagittal planes The measurements were taken with the subject standing upright. Two repetitions of arm elevation were recorded in each plane for both the affected and unaffected side.
Results	Demographics The GH osteoarthritis and frozen shoulder groups were comparable in demographic and clinical characteristics except for age, duration of symptoms and maximal humeral elevation of the affected shoulder in the frontal plane. The GH osteoarthritis group were older with longer disease duration as compared to the frozen shoulder group. p<0.001 The maximal humeral elevation of the affected frozen shoulder in the frontal plane was significantly lower than in those with GH osteoarthritis. p=0.01 The maximal humeral elevation of the unaffected side did not differ significantly between the GH and the FS groups. This held true in both the frontal and sagittal planes. Scapular Orientation at rest Scapular orientation at rest did not differ significantly on either the affected or unaffected sides between the 2 groups Scapular Upward Rotation with humeral movement (SHR) Scapular lateral rotation was significantly higher for the affected shoulders in both groups in both planes for all elevations there was no difference in scapular tilt between affected and unaffected sides of either the GH or FS groups Variables influencing scapular mobility Protraction was significantly lower in FS compared to GH osteoarthritis during arm elevation in the frontal plane but not in the sagittal plane Scapulohumeral rhythm (upward rotation) was higher in the FS compared to the GH osteoarthritic shoulder Disease duration had a fair to moderate correlation with SHR in the GH group but not with the FS group, in both planes. As the duration of disease increased, upward rotation increased. In both groups and both planes, there was a fair to moderate negative correlation between maximal humeral elevation and SHR. As maximal humeral elevation decreased there was a similar increase in upward rotation of the scapula.
Conclusions	This research provides evidence that scapular motion is affected by glenohumeral dysfunction, and/or that scapular dyskinesis may contribute to, or result in glenohumeral dysfunction. The increase in scapular upward rotation to compensate for a lack of GH abduction may be a great example of "relative flexibility."
Conclusions of the Researchers	Results confirmed that those people presenting with limited arm elevation due to glenohumeral osteoarthritis or frozen shoulder show increased scapular upward rotation. This restriction is most notable with movement in the frontal plane. Additionally, the increase of upward rotation in the presence of limited arm elevation is greater with frozen shoulder than with GH osteoarthritis. Also of note was the observation that scapular protraction and retraction movement is also altered when humeral elevation is limited. This was more notable in the FS group and in the frontal plane

Scapulohumeral Rhythm - http://http://physioworks.com.au/Injuries-Conditions/Regions/scapulohumeral_pattern.png

Review & Commentary: Mobility of the shoulder complex involves combined motions of both the scapulothoracic and glenohumeral joints. The two joints must be coordinated in order to perform full arm elevation. Previous studies have demonstrated a clear correlation between scapular and GH motion, and have also shown that a reproducible pattern of scapular kinematics exists during arm elevation. Specifically it has been shown that scapular upward rotation varies linearly with humeral angle and contributes to approximately 30-40% of the overall arm elevation in healthy shoulders of adults. This correlation of movement has been named scapulohumeral rhythm (SHR) (Dayanidhi et al., 2005, Fayed et al., 2006; McClure et al., 2001)

What has not been thoroughly explored in previous studies is the affect different disease processes have on SHR. Several disorders of the shoulder complex could be responsible for limited arm elevation, and each disorders may contribute to a loss in range of motion differently. This study used 3D kinematics to investigate and describe the mobility of the glenohumeral and scapulothoracic joints, resulting in a better understanding of scapular dyskinesis as it relates to frozen shoulder and glenohumeral osteoarthritis.

The methodology of this research was sound but it had its limitations. In general, the average age of onset of those affected by frozen shoulder and those affected by glenohumeral osteoarthritis is nearly 20 years different and the age difference may have impacted the results in the study (mean age in the GH group = 72.4; mean age in the FS group = 48.4). Further, there was a significant difference in the duration of symptoms between the two groups. Although these trends would be expected given the two diagnosis compared in this study, we must also consider that duration of symptoms and age of the individuals may have contributed to, or be the cause of the larger changes in scapular kinematics seen in the glenohumeral arthritis group.

Why is this study important? This study demonstrates the importance of considering the mobility of the scapula when addressing limitations in functional arm elevation and glenohumeral motion. Additionally, it confirms that the mechanics involved in limited arm elevation are similar with both glenohumeral osteoarthritis and frozen shoulder.

How does it affect practice? Despite the disease processes examined in this study being identified as specific to the glenohumeral joint, motion of the scapula was significantly altered. Treatment of shoulder dysfunction should not be limited to the GH joint alone, and should include intervention for optimizing scapular mobility and scapulohumeral motion (SHR). At the very least, improving scapular mobility and SHR may be an opportunity to enhance function and reduce painful ranges of motion when treatment of the glenohumeral joint may or may not be effective (inflammatory phase of FS or late stages of GH osteoarthritis.

How does it relate to Brookbush Institute Content?

This study shows a correlation between glenohumeral and scapular dyskinesis, similar to those found in individuals exhibiting Upper Body Dysfunction (UBD) . Interestingly, the limitations in shoulder mobility lead very specifically to the best scapular motion capable (upward rotation) of compensating for motion. This could be viewed as a very clear example of "relative flexibility" (Shirley A. Sahrmann), a concept that contributes greatly to our understanding of movement impairment/postural dysfunction . Further, the dysfunctional relationship between two separate joint structures examined in this study, may be viewed as an example of "regional interdependence" (although many would consider the shoulder girdle to be a single joint complex). Again this concept influences our understanding of human movement, as well as our assessment and treatment strategies at the Brookbush Institute - The location of pain is a clue that should only be weighed as heavily as the results of any other test in your movement assessment. Last, we come back to the "chicken or the egg" paradox in human movement. Did the scapular dyskinesis noted in this study result from glenohumeral pathology or contribute to glenohumeral pathology? As these studies do not predate the diagnosis of pain or treatment, it is not beyond reason to consider that the changes in scapular kinematics may have contributed to the painful condition of the shoulder.

Techniques for enhancing scapular motion:

Levator Scapulae Release

Pectoralis Minor Release

Rhomboid Release

Crucifixion Stretch

Cobra on Foam Roll

Bibliography

S. Dayanidhi, M. Orlin, S. Kozin, S. Duff, A. Karduna. Scapular kinematics during humeral elevation in adults and children. Clinical Biomechanics (Bristol, Avon), 20 (2005), pp. 600–606
F. Fayad, G. Hoffmann, S. Hanneton, C. Yazbeck, M.M. Lefevre-Colau, S. Poiraudeau, M. Revel, A. Roby-Brami. 3-D scapular kinematics during arm elevation: effect of motion velocity. Clinical Biomechanics (Bristol, Avon), 21 (2006), pp. 932–941
P.W. McClure, L.A. Michener, B.J. Sennett, A.R. Karduna. Direct 3-dimensional measurement of scapular kinematics during dynamic movements in vivo. Journal of Shoulder and Elbow Surgery, 10 (2001), pp. 269–277

Questions, comments, and criticisms are welcomed and encouraged -

Glenohumeral Osteoarthritis and Frozen Shoulder Alters Scapular Kinematics

Research Review: Glenohumeral Osteoarthritis and Frozen Shoulder Alters Scapular Kinematics

Techniques for enhancing scapular motion:

Bibliography

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