The Open Orthopaedics Journal




ISSN: 1874-3250 ― Volume 13, 2019
RESEARCH ARTICLE

Muscle Weakness in the Empty and Full Can Tests Cannot Differentiate Rotator Cuff Tear from Cervical Spondylotic Amyotrophy: Pain Provocation is a Useful Finding



Eiichiro Iwata1, *, Hideki Shigematsu1, Kazuya Inoue1, Takuya Egawa1, Yoshihiro Sakamoto2, Yasuhito Tanaka1
1 Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashiharashi, Nara 634-8522, Japan
2 Sakamoto Orthopedic Clinic, Nara, Japan

Abstract

Purpose:

Rotator cuff tears and cervical spondylotic amyotrophy (CSA) are often confused as the main symptom in those with difficulty in shoulder elevation. Empty and full can tests are frequently used for the clinical diagnosis of rotator cuff tears. The aim of the present study was to investigate whether the empty and full can test results can help differentiate rotator cuff tears from CSA.

Methods:

Twenty-seven consecutive patients with rotator cuff tears and 25 with CSA were enrolled. We prospectively performed empty and full can tests in patients with rotator cuff tears and CSA. The following signs were considered positive: (a) muscle weakness during the empty can test, (b) muscle weakness during the full can test, (c) pain provocation during the empty can test, and (d) pain provocation during the full can test. We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of rotator cuff tears for each positive finding.

Results:

The sensitivity and specificity of each index were as follows (sensitivity, specificity, PPV, NPV): (a) 77.8%, 0%, 45.7%, 0%; (b) 66.7%, 4.0%, 42.9%, 10.0%; (c) 88.9%, 96.0%, 96.0%, 88.9%; and (d) 74.1%, 96.0%, 95.2%, 77.4%. There were significant differences for each index.

Conclusion:

Muscle weakness during the empty and full can tests was not useful in differentiating rotator cuff tears from CSA because of low specificity and PPV. However, pain provocation was useful in differentiating these two conditions because of high specificity and PPV.

Keywords: Biceps, Rotator cuff tear, Cervical spondylotic amyotrophy, Full can test, Empty can test, Pain provocation, Muscle weakness.


Article Information


Identifiers and Pagination:

Year: 2017
Volume: 11
First Page: 1081
Last Page: 1086
Publisher Id: TOORTHJ-11-1081
DOI: 10.2174/1874325001711011081

Article History:

Received Date: 02/08/2017
Revision Received Date: 14/08/2017
Acceptance Date: 11/09/2017
Electronic publication date: 30/09/2017
Collection year: 2017`

Article Metrics:

CrossRef Citations:
0

Total Statistics:

Full-Text HTML Views: 2037
Abstract HTML Views: 1019
PDF Downloads: 665
ePub Downloads: 500
Total Views/Downloads: 4221

Unique Statistics:

Full-Text HTML Views: 1161
Abstract HTML Views: 654
PDF Downloads: 329
ePub Downloads: 234
Total Views/Downloads: 2378
Geographical View

© 2017 Iwata et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to this author at the Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara-shi, Nara 634-8522, Japan; Tel: +81-744-29-8873; Fax: +81-744-29-4902; E-mail: iwata@naramed-u.ac.jp





1. INTRODUCTION

The causes of difficulty in shoulder elevation are often difficult to identify, as this complaint might originate from various shoulder and cervical spine disorders. Additionally, the age at occurrence of pathologies of the shoulder and cervical spine is similar, and these specifically occur in the aging population [1Gumina S, Carbone S, Albino P, Gurzi M, Postacchini F. Arm Squeeze Test: A new clinical test to distinguish neck from shoulder pain. Eur Spine J 2013; 22(7): 1558-63.
[http://dx.doi.org/10.1007/s00586-013-2788-3] [PMID: 23604976]
, 2Katz JS, Saperstein DS, Wolfe G, et al. Cervicobrachial involvement in diabetic radiculoplexopathy. Muscle Nerve 2001; 24(6): 794-8.
[http://dx.doi.org/10.1002/mus.1071] [PMID: 11360263]
] and are often misdiagnosed. Among these, rotator cuff tears and cervical spondylotic amyotrophy (CSA) are often confused, as one of the main symptoms in both is difficulty in shoulder elevation.

CSA is classified as the proximal or distal type [3Kameyama T, Ando T, Yanagi T, Yasui K, Sobue G. Cervical spondylotic amyotrophy. Magnetic resonance imaging demonstration of intrinsic cord pathology. Spine 1998; 23(4): 448-52.
[http://dx.doi.org/10.1097/00007632-199802150-00008] [PMID: 9516699]
-5Matsunaga S, Sakou T, Imamura T, Morimoto N. Dissociated motor loss in the upper extremities. Clinical features and pathophysiology. Spine 1993; 18(14): 1964-7.
[http://dx.doi.org/10.1097/00007632-199310001-00007] [PMID: 8272944]
]. The clinical characteristics of the proximal type of CSA include muscle atrophy in the upper extremities, the absence of or insignificant sensory deficits and lower-extremity symptoms, and weakness of the deltoid and biceps muscles, which often causes dropped shoulder syndrome [3Kameyama T, Ando T, Yanagi T, Yasui K, Sobue G. Cervical spondylotic amyotrophy. Magnetic resonance imaging demonstration of intrinsic cord pathology. Spine 1998; 23(4): 448-52.
[http://dx.doi.org/10.1097/00007632-199802150-00008] [PMID: 9516699]
-7Yanagi T, Kato H, Sobue I. Clinical characteristics of cervical spondylotic amyotrophy Rinsho shinkeigaku. = Clinical neurology 1976; 16(7): 520-28.].

While one of the major symptoms of rotator cuff tears is difficulty in shoulder elevation, rotator cuff tears usually involve the supraspinatus tendon [8Codman EA. The shoulder 2nd ed. 1934; 262-312., 9Gschwend N, Ivosević-Radovanović D, Patte D. Rotator cuff tear-relationship between clinical and anatomopathological findings. Arch Orthop Trauma Surg 1988; 107(1): 7-15.
[http://dx.doi.org/10.1007/BF00463518] [PMID: 3345138]
]; therefore, the diagnosis of a rotator cuff tear is mainly based on the diagnosis of a torn supraspinatus tendon. The empty and full can tests are frequently used for the clinical diagnosis of rotator cuff tears, which elicit weakness or pain secondary to a torn supraspinatus tendon [10Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982; 10(6): 336-9.
[http://dx.doi.org/10.1177/036354658201000602] [PMID: 7180952]
, 11Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength. An electromyographic investigation. Am J Sports Med 1996; 24(5): 581-8.
[http://dx.doi.org/10.1177/036354659602400504] [PMID: 8883676]
]. Some authors reported the clinical usefulness of the empty and full can tests for determining the presence of a torn supraspinatus tendon [12Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
-14Kelly BT, Kadrmas WR, Kirkendall DT, Speer KP. Optimal normalization tests for shoulder muscle activation: An electromyographic study 1996.
[http://dx.doi.org/10.1002/jor.1100140421]
].

Usually, conservative therapy is effective for CSA, but surgery is sometimes needed if conservative therapy is ineffective. The duration of symptoms is one of the risk factors for poor outcomes after surgical treatment [15Tauchi R, Imagama S, Inoh H, et al. Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study. Eur Spine J 2013; 22(1): 156-61.
[http://dx.doi.org/10.1007/s00586-012-2506-6] [PMID: 23001450]
, 16Uchida K, Nakajima H, Yayama T, et al. Anterior and posterior decompressive surgery for progressive amyotrophy associated with cervical spondylosis: a retrospective study of 51 patients. J Neurosurg Spine 2009; 11(3): 330-7.
[http://dx.doi.org/10.3171/2009.3.SPINE08635] [PMID: 19769515]
], so early diagnosis is very important.

If problems with shoulder elevation due to a rotator cuff tear are suspected, the empty and full can tests are performed. We hypothesized that these tests could also be used to differentiate rotator cuff tears from CSA. Thus, the aim of the present study was to investigate whether the empty and full can tests could be used to differentiate rotator cuff tears from CSA.

2. MATERIALS AND METHODS

2.1. Patients

This study was approved by the institutional review board at our hospital (No.1135). We enrolled consecutive patients with rotator cuff tears who were scheduled to undergo surgery between January 2014 and August 2015 at our hospital (rotator cuff tear group) and those with CSA who had already diagnosed and presented to our clinic (CSA group).

2.2. Diagnosis of Rotator Cuff Tears

Rotator cuff tears were diagnosed by an orthopedic surgeon specializing in shoulder surgeries, and the diagnosis was based on the following criteria: (1) Magnetic resonance imaging (MRI) revealed a tear, and (2) the surgeon who operated recognized the tear intraoperatively. We excluded patients with cuff tear arthropathy.

2.3. Diagnosis of CSA

Proximal-type CSA was diagnosed by an orthopedic surgeon specializing in spine surgeries and the diagnosis was based on the following criteria: (1) the chief complaint was difficulty in shoulder elevation, no or insignificant sensory deficit, and no lower extremity symptoms; (2) MRI or computed tomography (CT) myelography revealing C5 or C6 nerve or anterior horn compression; and (3) electromyography performed by a neurologist excluded other diseases, such as amyotrophic lateral sclerosis or motor neuron disease.

2.4. Evaluation of Empty Can and Full Can Tests

First author (E.I.) performed the empty and full can tests in both rotator cuff tear and CSA patients. The empty can test [12Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
] was performed with the arm elevated to 90º in the scapular plane and in full internal rotation; the full can test [11Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength. An electromyographic investigation. Am J Sports Med 1996; 24(5): 581-8.
[http://dx.doi.org/10.1177/036354659602400504] [PMID: 8883676]
] was performed with the arm elevated to 90º in the scapular plane and at 45º external rotation. For each test, we evaluated muscle strength and the presence or absence of pain during the maneuver. Muscle strength was determined on the basis of manual muscle testing (MMT) [17Daniels L, Worthingham C. Muscle Testing Techniques of Manual Examination 4th ed. 1980; 118-20.]. We determined the presence of muscle weakness if the MMT was less than 3 or if both the MMT was 4 and the strength of the affected side was less than that of the intact contralateral side. Positive signs for each test are as follows: (a) muscle weakness during the empty can test, (b) muscle weakness during the full can test, (c) pain provocation during the empty can test, and (d) pain provocation during the full can test.

These physical findings were assessed in both rotator cuff tear and CSA patients. We assessed these physical examinations in the CSA patients immediately upon diagnosis of CSA and in the rotator cuff tear patients immediately before surgery.

2.5. Sensitivity and Specificity of the Empty and Full Can Tests

We calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for each physical examination, and statistical analysis was performed using the chi-squared test or Fisher’s exact probability test. In other analyses, differences in quantitative characteristics, such as age, were determined using the Student’s t-test. Differences in qualitative characteristics, such as sex, were analyzed with the chi-squared test. All statistical analyses were carried out with SPSS version 23.0 for Windows (IBM, Armonk, NY, USA). A p value of <0.05 was considered statistically significant.

3. RESULTS

3.1. Demographics

Twenty-seven patients with rotator cuff tears and 25 with CSA were enrolled in the present study. The rotator cuff tear group comprised 17 men and 10 women; the CSA group comprised 17 men and 8 women. The mean age was 64.1 years and 69.8 years in the rotator cuff tear and CSA groups, respectively. There was a significant difference with respect to age between the groups, but no difference in sex (Table 1).

Table 1
Demographic data of the patients included in the study.


3.2. Site of Rotator Cuff Tears

The sites of rotator cuff tears are presented in Table 2. The supraspinatus tendon was involved in all 27 cases.

Table 2
Site of rotator cuff tears.


3.3. Sensitivity and Specificity of the Empty and Full Can Tests

The sensitivity, specificity, PPV and NPV of each positive sign are as follows: (a) muscle weakness during the empty can test: sensitivity 77.8%, specificity 0%, PPV 45.7%, NPV 0%; (b) muscle weakness during the full can test: sensitivity 66.7%, specificity 4.0%, PPV 42.9%, NPV 10.0%; (c) pain provocation during the empty can test: sensitivity 88.9%, specificity 96.0%, PPV 96.0%, NPV 88.9%; and (d) pain provocation during the full can test: sensitivity 74.1%, specificity 96.0%, PPV 95.2%, NPV 77.4%. These were statistically significant differences between groups (Table 3).

Table 3
Sensitivity and specificity for each positive sign.


4. DISCUSSION

In the present study, the empty and full can tests were performed in both rotator cuff tear and CSA patients to investigate whether these two tests could differentiate rotator cuff tears from CSA. Both tests showed low specificity and PPV for muscle weakness; therefore, these findings might show a high positive rate in patients with CSA. Pain provocation showed high specificity and PPV in both tests. In addition, pain in the empty can test showed high sensitivity (88.9%). Similar to previous reports, the full can test was more accurate than was the empty can test for the clinical diagnosis of rotator cuff tears; this was because avoiding of the risk of mechanical impingement can lead to pain provocation [12Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
-14Kelly BT, Kadrmas WR, Kirkendall DT, Speer KP. Optimal normalization tests for shoulder muscle activation: An electromyographic study 1996.
[http://dx.doi.org/10.1002/jor.1100140421]
, 18Graichen H, Bonel H, Stammberger T, Englmeier KH, Reiser M, Eckstein F. Subacromial space width changes during abduction and rotation--a 3-D MR imaging study. Surg Radiol Anat 1999; 21(1): 59-64.
[http://dx.doi.org/10.1007/BF01635055] [PMID: 10370995]
]. However, pain provocation was useful in the differential diagnosis of rotator cuff tear from CSA, and is an important finding in the present study.

Rotator cuff tears usually involve the supraspinatus tendon [8Codman EA. The shoulder 2nd ed. 1934; 262-312., 9Gschwend N, Ivosević-Radovanović D, Patte D. Rotator cuff tear-relationship between clinical and anatomopathological findings. Arch Orthop Trauma Surg 1988; 107(1): 7-15.
[http://dx.doi.org/10.1007/BF00463518] [PMID: 3345138]
]; therefore, the diagnosis of rotator cuff tear is mainly based on the diagnosis of a torn supraspinatus tendon. In the present study, the supraspinatus tendon was involved in all 27 cases. Jobe et al. reported that a test to assess the ability of the affected shoulder to maintain the arm at 90º elevation in the scapular plane and in full internal rotation elicits weakness or pain secondary to a torn supraspinatus tendon (the empty can test) [10Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982; 10(6): 336-9.
[http://dx.doi.org/10.1177/036354658201000602] [PMID: 7180952]
]. Subsequently, Kelly et al. proposed a new test to assess the function of the supraspinatus tendon to maintain the arm at 90º elevation in the scapular plane and at 45º external rotation and that elicited weakness or pain, and named this the full can test [11Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength. An electromyographic investigation. Am J Sports Med 1996; 24(5): 581-8.
[http://dx.doi.org/10.1177/036354659602400504] [PMID: 8883676]
]. These two physical examinations are frequently used for the diagnosis of rotator cuff tears. Some authors reported the clinical usefulness of the empty and full can tests for determining the presence of a torn supraspinatus tendon. Itoi et al. reported that the full can test may be more beneficial in the clinical setting, considering the pain provocation [13Itoi E, Kido T, Sano A, Urayama M, Sato K. Which is more useful, the “full can test” or the “empty can test,” in detecting the torn supraspinatus tendon? Am J Sports Med 1999; 27(1): 65-8.
[http://dx.doi.org/10.1177/03635465990270011901] [PMID: 9934421]
]. Further, another author reported that pain provocation was more frequent during the performance of the empty can test than it was during the full can test, and the full can test more accurately evaluated muscle weakness [12Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
, 14Kelly BT, Kadrmas WR, Kirkendall DT, Speer KP. Optimal normalization tests for shoulder muscle activation: An electromyographic study 1996.
[http://dx.doi.org/10.1002/jor.1100140421]
]. Graichen et al. reported that a three-dimensional magnetic resonance imaging study demonstrated that internally rotated arm abduction decreases the size of the subacromial space [18Graichen H, Bonel H, Stammberger T, Englmeier KH, Reiser M, Eckstein F. Subacromial space width changes during abduction and rotation--a 3-D MR imaging study. Surg Radiol Anat 1999; 21(1): 59-64.
[http://dx.doi.org/10.1007/BF01635055] [PMID: 10370995]
]. This avoids the risk of mechanical impingement that leads to pain, and therefore, the full can test is more accurate than the empty can test for the clinical diagnosis of rotator cuff tears.

One of the major symptoms of rotator cuff tear is difficulty in shoulder elevation. This complaint might originate from cervical pathologies. The chief complaint of patients with cervical pathologies, especially CSA, is also difficulty in shoulder elevation [3Kameyama T, Ando T, Yanagi T, Yasui K, Sobue G. Cervical spondylotic amyotrophy. Magnetic resonance imaging demonstration of intrinsic cord pathology. Spine 1998; 23(4): 448-52.
[http://dx.doi.org/10.1097/00007632-199802150-00008] [PMID: 9516699]
-7Yanagi T, Kato H, Sobue I. Clinical characteristics of cervical spondylotic amyotrophy Rinsho shinkeigaku. = Clinical neurology 1976; 16(7): 520-28.]. In addition, the predilection age for these two conditions is similar, especially in the aging population [1Gumina S, Carbone S, Albino P, Gurzi M, Postacchini F. Arm Squeeze Test: A new clinical test to distinguish neck from shoulder pain. Eur Spine J 2013; 22(7): 1558-63.
[http://dx.doi.org/10.1007/s00586-013-2788-3] [PMID: 23604976]
, 2Katz JS, Saperstein DS, Wolfe G, et al. Cervicobrachial involvement in diabetic radiculoplexopathy. Muscle Nerve 2001; 24(6): 794-8.
[http://dx.doi.org/10.1002/mus.1071] [PMID: 11360263]
]. Therefore, CSA is often misdiagnosed as rotator cuff tear. Conservative therapy is usually effective in CSA; however, if it is ineffective, surgery is needed [15Tauchi R, Imagama S, Inoh H, et al. Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study. Eur Spine J 2013; 22(1): 156-61.
[http://dx.doi.org/10.1007/s00586-012-2506-6] [PMID: 23001450]
, 16Uchida K, Nakajima H, Yayama T, et al. Anterior and posterior decompressive surgery for progressive amyotrophy associated with cervical spondylosis: a retrospective study of 51 patients. J Neurosurg Spine 2009; 11(3): 330-7.
[http://dx.doi.org/10.3171/2009.3.SPINE08635] [PMID: 19769515]
]. Tauchi et al. reported that early surgery was recommended for CSA patients in whom conservative treatment was unsuccessful, based on clinical status before surgery, including symptom duration [15Tauchi R, Imagama S, Inoh H, et al. Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study. Eur Spine J 2013; 22(1): 156-61.
[http://dx.doi.org/10.1007/s00586-012-2506-6] [PMID: 23001450]
]. Uchida et al. reported that a long preoperative period strongly correlated with less improvement in muscle power [16Uchida K, Nakajima H, Yayama T, et al. Anterior and posterior decompressive surgery for progressive amyotrophy associated with cervical spondylosis: a retrospective study of 51 patients. J Neurosurg Spine 2009; 11(3): 330-7.
[http://dx.doi.org/10.3171/2009.3.SPINE08635] [PMID: 19769515]
]. Early diagnosis is therefore vital in CSA.

Diagnosis of rotator cuff tears is comprehensively based on physical findings, disease course, and imaging study, such as with magnetic resonance imaging [12Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
, 19Hegedus EJ, Goode AP, Cook CE, et al. Which physical examination tests provide clinicians with the most value when examining the shoulder? Update of a systematic review with meta-analysis of individual tests. Br J Sports Med 2012; 46(14): 964-78.
[http://dx.doi.org/10.1136/bjsports-2012-091066] [PMID: 22773322]
, 20Hermans J, Luime JJ, Meuffels DE, Reijman M, Simel DL, Bierma-Zeinstra SM. Does this patient with shoulder pain have rotator cuff disease?: The Rational Clinical Examination systematic review. JAMA 2013; 310(8): 837-47.
[http://dx.doi.org/10.1001/jama.2013.276187] [PMID: 23982370]
]. However, imaging generally causes a delay in diagnosis and entails a high cost, while physical findings are convenient and enable rapid diagnosis. Therefore, we have identified physical findings (i.e., those of empty and full can tests) that would be useful for differentiating between rotator cuff tear and CSA to prevent misdiagnosing CSA as rotator cuff tear, especially on initial diagnosis.

Our study has several limitations. First, we did not evaluate the coexistence of rotator cuff tears and CSA, i.e., patients with rotator cuff tear did not undergo examinations for CSA and patients with CSA did not undergo examinations for rotator cuff tears. Second, we did not evaluate inter- and intra-observer errors. The examiner was only one person who specialized in spine surgery. Third, we did not conduct a power analysis to determine the appropriate sample size before conducting the present study. However, as there was a significant difference for each physical finding, a type 2 error (caused by a small sample size) might not have occurred. Fourth, the examiner was not blinded from the gold standard diagnosis when performing the test. To eliminate these issues, we aim to conduct a similar prospective study in a large cohort.

We suggest that not only evaluation of muscle weakness but also pain provocation should be conducted during the empty and full can tests for the diagnosis of rotator cuff tears. If pain provocation is positive, CSA could be excluded because of the high specificity and PPV of this test. If only muscle weakness is positive, the possibility of CSA should be considered, because of the low specificity and PPV. Therefore, we can prevent the misdiagnosis of CSA as rotator cuff tear and avoid delays in diagnosing CSA.

CONCLUSION

Muscle weakness in the empty and full can tests could not differentiate rotator cuff tears from CSA because of its low specificity and PPV; however, pain provocation was useful for differentiating these two conditions because of its high specificity and PPV.

FUNDING

There is no funding source.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

This article does not contain any studies with human participants or animals performed by any of the authors.

HUMAN AND ANIMAL RIGHTS

No Animals/Humans were used for studies that are base of this research.

CONSENT FOR PUBLICATION

Not applicable.

CONFLICT OF INTEREST

The authors declare no conflict of interest, financial or otherwise.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Gumina S, Carbone S, Albino P, Gurzi M, Postacchini F. Arm Squeeze Test: A new clinical test to distinguish neck from shoulder pain. Eur Spine J 2013; 22(7): 1558-63.
[http://dx.doi.org/10.1007/s00586-013-2788-3] [PMID: 23604976]
[2] Katz JS, Saperstein DS, Wolfe G, et al. Cervicobrachial involvement in diabetic radiculoplexopathy. Muscle Nerve 2001; 24(6): 794-8.
[http://dx.doi.org/10.1002/mus.1071] [PMID: 11360263]
[3] Kameyama T, Ando T, Yanagi T, Yasui K, Sobue G. Cervical spondylotic amyotrophy. Magnetic resonance imaging demonstration of intrinsic cord pathology. Spine 1998; 23(4): 448-52.
[http://dx.doi.org/10.1097/00007632-199802150-00008] [PMID: 9516699]
[4] Keegan JJ. The cause of dissociated motor loss in the upper extremity with cervical spondylosis. J Neurosurg 1965; 23(5): 528-36.
[http://dx.doi.org/10.3171/jns.1965.23.5.0528] [PMID: 5858444]
[5] Matsunaga S, Sakou T, Imamura T, Morimoto N. Dissociated motor loss in the upper extremities. Clinical features and pathophysiology. Spine 1993; 18(14): 1964-7.
[http://dx.doi.org/10.1097/00007632-199310001-00007] [PMID: 8272944]
[6] Brain WR, Northfield D, Wilkinson M. The neurological manifestations of cervical spondylosis. Brain 1952; 75(2): 187-225.
[http://dx.doi.org/10.1093/brain/75.2.187] [PMID: 14934989]
[7] Yanagi T, Kato H, Sobue I. Clinical characteristics of cervical spondylotic amyotrophy Rinsho shinkeigaku. = Clinical neurology 1976; 16(7): 520-28.
[8] Codman EA. The shoulder 2nd ed. 1934; 262-312.
[9] Gschwend N, Ivosević-Radovanović D, Patte D. Rotator cuff tear-relationship between clinical and anatomopathological findings. Arch Orthop Trauma Surg 1988; 107(1): 7-15.
[http://dx.doi.org/10.1007/BF00463518] [PMID: 3345138]
[10] Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982; 10(6): 336-9.
[http://dx.doi.org/10.1177/036354658201000602] [PMID: 7180952]
[11] Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength. An electromyographic investigation. Am J Sports Med 1996; 24(5): 581-8.
[http://dx.doi.org/10.1177/036354659602400504] [PMID: 8883676]
[12] Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996; 5(4): 307-13.
[http://dx.doi.org/10.1016/S1058-2746(96)80058-9] [PMID: 8872929]
[13] Itoi E, Kido T, Sano A, Urayama M, Sato K. Which is more useful, the “full can test” or the “empty can test,” in detecting the torn supraspinatus tendon? Am J Sports Med 1999; 27(1): 65-8.
[http://dx.doi.org/10.1177/03635465990270011901] [PMID: 9934421]
[14] Kelly BT, Kadrmas WR, Kirkendall DT, Speer KP. Optimal normalization tests for shoulder muscle activation: An electromyographic study 1996.
[http://dx.doi.org/10.1002/jor.1100140421]
[15] Tauchi R, Imagama S, Inoh H, et al. Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study. Eur Spine J 2013; 22(1): 156-61.
[http://dx.doi.org/10.1007/s00586-012-2506-6] [PMID: 23001450]
[16] Uchida K, Nakajima H, Yayama T, et al. Anterior and posterior decompressive surgery for progressive amyotrophy associated with cervical spondylosis: a retrospective study of 51 patients. J Neurosurg Spine 2009; 11(3): 330-7.
[http://dx.doi.org/10.3171/2009.3.SPINE08635] [PMID: 19769515]
[17] Daniels L, Worthingham C. Muscle Testing Techniques of Manual Examination 4th ed. 1980; 118-20.
[18] Graichen H, Bonel H, Stammberger T, Englmeier KH, Reiser M, Eckstein F. Subacromial space width changes during abduction and rotation--a 3-D MR imaging study. Surg Radiol Anat 1999; 21(1): 59-64.
[http://dx.doi.org/10.1007/BF01635055] [PMID: 10370995]
[19] Hegedus EJ, Goode AP, Cook CE, et al. Which physical examination tests provide clinicians with the most value when examining the shoulder? Update of a systematic review with meta-analysis of individual tests. Br J Sports Med 2012; 46(14): 964-78.
[http://dx.doi.org/10.1136/bjsports-2012-091066] [PMID: 22773322]
[20] Hermans J, Luime JJ, Meuffels DE, Reijman M, Simel DL, Bierma-Zeinstra SM. Does this patient with shoulder pain have rotator cuff disease?: The Rational Clinical Examination systematic review. JAMA 2013; 310(8): 837-47.
[http://dx.doi.org/10.1001/jama.2013.276187] [PMID: 23982370]

Endorsements



"Open access will revolutionize 21st century knowledge work and accelerate the diffusion of ideas and evidence that support just in time learning and the evolution of thinking in a number of disciplines."


Daniel Pesut
(Indiana University School of Nursing, USA)

"It is important that students and researchers from all over the world can have easy access to relevant, high-standard and timely scientific information. This is exactly what Open Access Journals provide and this is the reason why I support this endeavor."


Jacques Descotes
(Centre Antipoison-Centre de Pharmacovigilance, France)

"Publishing research articles is the key for future scientific progress. Open Access publishing is therefore of utmost importance for wider dissemination of information, and will help serving the best interest of the scientific community."


Patrice Talaga
(UCB S.A., Belgium)

"Open access journals are a novel concept in the medical literature. They offer accessible information to a wide variety of individuals, including physicians, medical students, clinical investigators, and the general public. They are an outstanding source of medical and scientific information."


Jeffrey M. Weinberg
(St. Luke's-Roosevelt Hospital Center, USA)

"Open access journals are extremely useful for graduate students, investigators and all other interested persons to read important scientific articles and subscribe scientific journals. Indeed, the research articles span a wide range of area and of high quality. This is specially a must for researchers belonging to institutions with limited library facility and funding to subscribe scientific journals."


Debomoy K. Lahiri
(Indiana University School of Medicine, USA)

"Open access journals represent a major break-through in publishing. They provide easy access to the latest research on a wide variety of issues. Relevant and timely articles are made available in a fraction of the time taken by more conventional publishers. Articles are of uniformly high quality and written by the world's leading authorities."


Robert Looney
(Naval Postgraduate School, USA)

"Open access journals have transformed the way scientific data is published and disseminated: particularly, whilst ensuring a high quality standard and transparency in the editorial process, they have increased the access to the scientific literature by those researchers that have limited library support or that are working on small budgets."


Richard Reithinger
(Westat, USA)

"Not only do open access journals greatly improve the access to high quality information for scientists in the developing world, it also provides extra exposure for our papers."


J. Ferwerda
(University of Oxford, UK)

"Open Access 'Chemistry' Journals allow the dissemination of knowledge at your finger tips without paying for the scientific content."


Sean L. Kitson
(Almac Sciences, Northern Ireland)

"In principle, all scientific journals should have open access, as should be science itself. Open access journals are very helpful for students, researchers and the general public including people from institutions which do not have library or cannot afford to subscribe scientific journals. The articles are high standard and cover a wide area."


Hubert Wolterbeek
(Delft University of Technology, The Netherlands)

"The widest possible diffusion of information is critical for the advancement of science. In this perspective, open access journals are instrumental in fostering researches and achievements."


Alessandro Laviano
(Sapienza - University of Rome, Italy)

"Open access journals are very useful for all scientists as they can have quick information in the different fields of science."


Philippe Hernigou
(Paris University, France)

"There are many scientists who can not afford the rather expensive subscriptions to scientific journals. Open access journals offer a good alternative for free access to good quality scientific information."


Fidel Toldrá
(Instituto de Agroquimica y Tecnologia de Alimentos, Spain)

"Open access journals have become a fundamental tool for students, researchers, patients and the general public. Many people from institutions which do not have library or cannot afford to subscribe scientific journals benefit of them on a daily basis. The articles are among the best and cover most scientific areas."


M. Bendandi
(University Clinic of Navarre, Spain)

"These journals provide researchers with a platform for rapid, open access scientific communication. The articles are of high quality and broad scope."


Peter Chiba
(University of Vienna, Austria)

"Open access journals are probably one of the most important contributions to promote and diffuse science worldwide."


Jaime Sampaio
(University of Trás-os-Montes e Alto Douro, Portugal)

"Open access journals make up a new and rather revolutionary way to scientific publication. This option opens several quite interesting possibilities to disseminate openly and freely new knowledge and even to facilitate interpersonal communication among scientists."


Eduardo A. Castro
(INIFTA, Argentina)

"Open access journals are freely available online throughout the world, for you to read, download, copy, distribute, and use. The articles published in the open access journals are high quality and cover a wide range of fields."


Kenji Hashimoto
(Chiba University, Japan)

"Open Access journals offer an innovative and efficient way of publication for academics and professionals in a wide range of disciplines. The papers published are of high quality after rigorous peer review and they are Indexed in: major international databases. I read Open Access journals to keep abreast of the recent development in my field of study."


Daniel Shek
(Chinese University of Hong Kong, Hong Kong)

"It is a modern trend for publishers to establish open access journals. Researchers, faculty members, and students will be greatly benefited by the new journals of Bentham Science Publishers Ltd. in this category."


Jih Ru Hwu
(National Central University, Taiwan)


Browse Contents




Webmaster Contact: info@benthamopen.net
Copyright © 2019 Bentham Open