Original articleContact forces in the subacromial space: Effects of scapular orientation
Section snippets
Materials and methods
Eight human glenohumeral joints (mean age, 76 years) were harvested from fresh cadavers and dissected to the level of the rotator cuff. Specimens were stored frozen and thawed just before experimentation. On the humerus, all soft tissue between the rotator cuff and distal condyles was removed. On the scapula, the inferomedial portions of the infraspinatus, teres minor, and subscapularis were resected. The glenohumeral capsule was vented, thus eliminating any effects of intraarticular pressure.
Results
As expected, during the initial translation period of most trials, the force data before and after removal of the acromion were very similar. It was only after larger displacements were achieved that these 2 curves diverged (Figure 4, A). Once the difference between these 2 curves was calculated, it was relatively straightforward to determine the displacement at 20 N (Figure 4, B). This displacement value was defined as the subacromial clearance. The reliability of this clearance measurement
Discussion
Impingement syndrome is one of the most commonly diagnosed shoulder conditions. It is characterized by a mechanical compression of the soft tissues in the subacromial space with symptoms that typically include shoulder pain, stiffness, tenderness, and weakness. Although the etiology of rotator cuff disease is still not completely understood, many researchers and clinicians believe that there is an association between subacromial contact and the development of rotator cuff disease. On the basis
References (36)
- et al.
Radiographic assessment of scapular rotational tilt in chronic shoulder impingement syndrome
J Orthop Sci
(2001) - et al.
Three-dimensional analysis of shoulder girdle and supraspinatus motion patterns in patients with impingement syndrome
J Orthop Res
(2001) - et al.
Scapular behavior in shoulder impingement syndrome
Arch Phys Med Rehabil
(2002) - et al.
Scapular inclination and inferior stability of the shoulder
J Shoulder Elbow Surg
(1992) - et al.
Scapular kinematicseffects of altering the Euler angle sequence of rotations
J Biomech
(2000) - et al.
Joint stability after total shoulder arthroplasty in a cadaver model
J Shoulder Elbow Surg
(1997) - et al.
Contact geometry at the undersurface of the acromion with and without a rotator cuff tear
Arthroscopy
(2001) - et al.
Direct 3-dimensional measurement of scapular kinematics during dynamic movements in vivo
J Shoulder Elbow Surg
(2001) Rehabilitation of common shoulder injuries
Clin Sports Med
(1989)- et al.
The measurement of subacromial contact pressure in patients with impingement syndrome
Arthroscopy
(1999)
A combined robotic/universal force sensor approach to determine in situ forces of knee ligaments
J Biomech
Superoinferior translation in the intact and vented glenohumeral joint
J Shoulder Elbow Surg
Shoulder impingement syndromeinfluence of shoulder position on rotator cuff impingement—an anatomic study
AJR Am J Roentgenol
Anatomic relationships in the shoulder impingement syndrome
Clin Orthop
Impingement syndrome and rotator cuff disease as repetitive motion disorders
Clin Orthop
Shoulder movements during abduction in the scapular plane
Arch Phys Med Rehabil
Excursion of the rotator cuff under the acromion. Patterns of subacromial contact
Am J Sports Med
Shoulder impingement syndromea critical review
Clin Orthop
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This work was supported by a grant from the Whitaker Foundation.