Anatomical and biomechanical mechanisms of subacromial impingement syndrome

Michener, Lori A.; McClure, Philip; Karduna, Andrew R.

doi:10.1016/s0268-0033(03)00047-0

Cited by 587 publications

(522 citation statements)

References 79 publications

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“…FHP can be linked to computer use, 28 carriage of backpacks, 29 use of smartphones, 16 headache, 30 mouth breathing, bad habit, 31 or shoulder overuse 15,23,32 (Table 1).…”

Section: Forward Head Posturementioning

confidence: 99%

“…[7][8][9] Failure of the head to align with the vertical axis of the body 3,10 (Fig 2) can lead to further malalignments in the body, namely, rounded shoulders and increased thoracic kyphosis, 11,12 to compensate 13 for the altered location of the LOG, leading to further impairments. 14 Combination of all these postural deviations is often known as "slouched posture" 15,16 or "slumped posture." 3,17 According to Kendall et al, 6 there should be vertical alignment between the midline of the shoulder and the mastoid process.…”

Section: Introductionmentioning

confidence: 99%

“…3,17 According to Kendall et al, 6 there should be vertical alignment between the midline of the shoulder and the mastoid process. If the acromion processes are more anteriorly positioned compared with the mastoid processes, a condition known as forward shoulder posture (FSP) or rounded shoulders or protracted shoulders 11,15 occurs (Fig 3); this condition is characterized by protracted, internally rotated, anteriorly tilted, elevated, and abducted scapula along with winging of scapula. 15,18,19 This poor alignment of the shoulders leads to greater torque production by gravitational forces, which is being offset by greater internal forces generated by muscles and other soft tissues around the shoulder.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature

Singla

Veqar

2017

Journal of Chiropractic Medicine

151

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Objective: The purpose of this review was to explore the association between forward head posture, rounded shoulders, and increased thoracic kyphosis. Methods: The PubMed, ERIC, and Cochrane databases were searched using the key words posture, head, shoulder, forward scapular posture, and thoracic kyphosis through December 2016. Results: Our initial search yielded 6840 research studies, 6769 of which were excluded because they either were duplicates or did not satisfy the inclusion criteria. After the abstracts of the remaining studies were read, 15 were assessed for eligibility, and only 4 papers were included in the present review. Cervical lordosis values were found to be significantly associated with thoracic kyphosis values. Also, there were significant correlations between rounded shoulders and increased thoracic kyphosis. Conclusion: Forward head posture, rounded shoulders, and increased thoracic kyphosis can exist alone or in any combination. (J Chiropr Med 2017;16:220-229)

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“…FHP can be linked to computer use, 28 carriage of backpacks, 29 use of smartphones, 16 headache, 30 mouth breathing, bad habit, 31 or shoulder overuse 15,23,32 (Table 1).…”

Section: Forward Head Posturementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature

Singla

Veqar

2017

Journal of Chiropractic Medicine

151

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“…Michener et al, 2003) yet very few studies have investigated rotator cuff strength in an SSI group and an asymptomatic group.The hypothesis that a significant difference in muscle strength would be found in the painful shoulder in the SSI group (cases) compared to the dominance matched shoulder in the control group has not been clearly identified in this study. Only one concentric variable (ER PT at 60 0 /second) was significantly different between the two groups.…”

Section: Discussionmentioning

confidence: 99%

“…Pain originates from the tissues within the subacromial space including the rotator cuff (N. Hanchard, Cummins, & Jeffries, 2004; J. S. Lewis, Green, & Dekel, 2001). In people with SSI it is proposed rotator cuff muscle weakness develops secondary to inflammation and degeneration that occurs as a result of mechanical compression from a structure external to the tendon, known as extrinsic SSI (Michener, McClure, & Karduna, 2003), or as a result of overuse and tension overload affecting the tendons intrinsically, as in tendinopathy, known as intrinsic SSI (Jeremy S ).…”

Section: Introductionmentioning

confidence: 99%

Isokinetic clinical assessment of rotator cuff strength in subacromial shoulder impingement

Land

Gordon

Watt

2017

Musculoskeletal Science and Practice

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Background: Current conservative management of subacromial shoulder impingement (SSI) includes generic strengthening exercises, especially for internal (IR) and external (ER) shoulder rotators. However, there is no evidence that the strength or the ratio of strength between these muscle groups is different between those with SSI (cases) and an asymptomatic population (controls).Objective: To identify if isokinetic rotator cuff strength or the ratio of strength is significantly different between cases and controls.Study Design: Case Control Study.Method: Fifty one cases with SSI and 51 asymptomatic controls matched for age, gender, hand dominance and physical activity level completed isokinetic peak torque glenohumeral IR and ER testing. Within the SSI group, 31 dominant limbs were symptomatic and 20 non-dominant limbs were symptomatic. IR and ER were measured separately using continuous reciprocal concentric (con) and eccentric (ecc) contraction cycles at a speed of 60 0 degrees per second and again at 120 0 degrees per second. Values of peak torque (PT), relative peak torque (RPT) and ratios were compared using independent t-tests between the SSI and asymptomatic groups.Results: Significant strength differences between the two groups were present only when the symptomatic SSI shoulder was the dominant shoulder (con ER PT at 60 0 /second, ecc ER PT at 120 0 /second, ecc ER RPT at 120 0 /second and ecc IR PT at 60 0 /second and 120 0 /second). Conclusions:Changes in rotator cuff strength in SSI may be related to limb dominance, which may have implications for strengthening regimes. Level of Evidence:Level 3a

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Can Acromioplasty Result in Impairment?

Melhorn¹,

Brooks²,

Talmage³

2011

AMA Guides® Newsletter

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To determine if an acromioplasty is impairing, an evaluator must know shoulder anatomy, the diagnosis or diagnoses, what treatment was provided, and the patient's present status. Over time, the earlier classification of shoulder impingement has been modified, and the current classification was adopted in 1994. At present, acromioplasty often is not the primary surgery but rather is one component of subacromial decompression with or without concomitant rotator cuff and/or intra-articular shoulder surgery. Until the sixth edition, the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) did not address the question whether acromioplasty itself constitutes an impairment. In the fourth and fifth editions of the AMA Guides, although open or arthroscopic acromioplasty commonly results in temporary shoulder pain, stiffness, and weakness, the surgical procedure itself, barring complication, results in no permanent impairment. According to the AMA Guides, Sixth Edition, if an acromioplasty eliminated impingement and resulted in no pain or significant objective findings at maximal medical impairment, no impairment occurred. Diagnosis-based impairment is considered the rating method of choice, but range of motion is used primarily in the physical examination adjustment grid. Further, surgical error and/or complications may result in ratable motion and/or strength deficits. The AMA Guides, Fourth and Fifth Editions, also provide a means to rate impairment due to any concomitant distal clavicular resection.

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Anatomical and biomechanical mechanisms of subacromial impingement syndrome

Cited by 587 publications

References 79 publications

Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature

Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature

Isokinetic clinical assessment of rotator cuff strength in subacromial shoulder impingement

Can Acromioplasty Result in Impairment?

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