Subscapularis Trigger Points as a Predictor for Frozen Shoulder Syndrome: Correlation Study

Journal of Environmental Treatment Techniques

2020, Volume 8, Issue 4, Pages: 1447-1449

J. Environ. Treat. Tech.

ISSN: 2309-1185

Journal web link: http://www.jett.dormaj.com

https://doi.org/10.47277/JETT/8(4)1449

Subscapularis Trigger Points as a Predictor for

Frozen Shoulder Syndrome: Correlation Study

Huda B. Abd Elhamed*, Ebtessam Fawzy Goma, Alaa El-din Abd El Hakem Balbaa

Department of Musculoskeletal Disorders and its Surgery Faculty of Physical Therapy, Cairo University, Egypt

Received: 06/06/2020

Accepted: 08/09/2020

Published: 20/12/2020

Abstract

Trigger points in the shoulder region muscles restrict movement of shoulder and create pain on movement and at rest. The key

muscle that must be examined is the subscapularis muscle. The aim of this study is to investigate the relationship between subscapularis

trigger with shoulder pain, shoulder abduction and shoulder externalrotation. 50 patients diagnosed with frozen shoulder. Data obtained

regarding pressure pain threshold (PPT) using pressure algometry, shoulder pain and disability index (SPADI)using questionnaire,

shoulder abduction and external rotation ROM using digital inclinometer were statistically analysed and compared. Strong negative

significant correlation between PPT with SPADI, strong positive significant correlation between PPT with shoulder abduction and

external rotation. Subscapularis trigger points in patients with frozen shoulder affect shoulder pain, shoulder abduction, and external

rotation.

Keywords: Frozen shoulder, SPADI, Subscapularis, Trigger points, Pressure pain threshold

Introduction

watershed effect on local vessels, Energy crisis, Production of

inflammatory agents, which sensitize local autonomic and

nociceptive (pain) fibers (5), the aim of the study is to

investigate the relationship between subscapularis trigger with

shoulder pain, shoulder abduction and shoulder external

rotation.

Frozen shoulder syndrome (FSS) is

condition

characterized by a painful, progressive loss of both active and

passive shouldermotion resultingfrom progressive fibrosis and

ultimate contracture of the glenohumeral joint capsule (1). The

most commonly affected movements were external rotation

and abduction of the gleno-humeral joint (2). Frozen shoulder

is very a common musculoskeletal pain condition that is

generally poorly identified and treated because the cause is

usually myofascial trigger points that are overlooked in most

practitioners’ initial education and training (3). Patients who

have trigger points often reports regional, persistent pain that

usually result in decreased range of motion of the muscle in

question (4). Trigger Points shorten muscles and actively

prevent them from lengthening, causing muscle weakness (3).

Trigger Points often are painful and this pain makes muscles

stay tense and this constant tension in the muscle will make the

trigger point worse, thus completing a continually worsening

cycle (3). The subscapularis is often at the very heart of the

problem with frozen shoulder (3). Trigger points keep the

subscapularis from lengthening, which it must do to allow any

movement involving outward rotation of the arm, including

raisingthe arm overhead. With a frozen shoulder, knowing how

to treat subscapularis trigger points is the key to recovery (3).

The actin and myosin myofilaments stop sliding over one

another. As a result, the sarcomere becomes turned to the

permanently 'switched-on' position, leading to a contraction.

This sustained dysfunction and sarcomere contraction leads to

local intracellular chemical changes including, Localized

ischemia, Increased metabolism needs, Increased energy

requiredto sustaincontraction, failed re-uptake of calcium ions

into the sarcoplasmic reticulum, Localized inflammation (to

facilitate repair), Compression or

1.1 Study Design

The study was designed as a correlation.

.2 Study participants

Fifty-six patients diagnosed with frozen shoulder referred

to the out-clinic of the Faculty of physical therapy, Cairo

University, were enrolled and assessed for their eligibility to

participate in the study, their age ranged from 40 to 60 years.

Exclusion criteria were Presence of polyarthritis or

neurological diseases or cervical neuropathy. Previous Intra-

articularcortisone injectionfor 6 months ago. Writteninformed

consent was obtained from all subjects before the baseline

evaluation. Ethical approval was obtainedfrom the institutional

review board at Faculty of physical therapy, Cairo University

before study commencement. The study followed the

Guidelines of Declaration of Helsinki on conduction of human

research (6). The inclusion criteria were patients who had

Patients diagnosed with idiopathic or secondary frozen

shoulder. Patients had subscapularis trigger points. Have a

painful and stiff shoulder for at least 3 months (stage two) Loss

of active and passive abduction shoulder and external rotation

range of motion.

.3 Outcome measures

Trigger points were measured using pressure algometry

consisting of a 1-cm diameter hard wide disk connected to a

dial gauge calibrated in kg/cm . Algometry is an objective

Corresponding author: Huda B. Abd Elhamed, Department of Musculoskeletal Disorders and its Surgery Faculty of Physical Therapy,

Cairo University, Egypt. E-mail: dr_huda_bader@yahoo.com

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Journal of Environmental Treatment Techniques

2020, Volume 8, Issue 4, Pages: 1447-1449

method of quantifying soft tissue tenderness and has been

shown to be a useful tool in the assessmentof TrPs (7, 8). Inter-

examiner reliability of the pressure algometry is good to

excellent (interclass correlation (ICC) = 0.75- 0.89) Also,

reliability may be enhanced when one examiner takes all

measurements (7, 8). Shoulder pain and disability index has

been shown to be responsive to change over time, in a variety

of patient populations and is able to discriminate adequately

between patients with improving and deteriorating conditions

Abduction-AROM was measured in the seated position,

with the trunk upright. The patient was asked to abduct the arm

with the thumb pointed up toward the ceiling and the elbow

extended (18).

Shoulder external rotation was measured in supine position

with the shoulder adducted and the elbow flexed to 90 degrees,

the wrist in neutral position, the patient was asked to rotate his

or her arm outward into external rotation, external rotation was

measured by placing the digital level to the forearm, parallel

with the midline of the ulna (18).

(

10). Digital inclinometerprofessional 9 inches’ multi-function

HUSKY digital level used to measure shoulder abduction and

external rotation. This is a digital level used to measure the

horizontal and vertical alignment of objects, with a measuring

range of 360 degrees the accuracy of digital display is ± 0.1º

for level and ± 0.2º for all angles (11).

Statistical analysis

Descriptive statistics of the general characteristics of the

subjects table (1). The frequency distribution of gender of the

study group table (2).data obtained regarding pressure pain

threshold (PPT), shoulder pain and disability index (SPADI),

shoulder abduction and external rotation ROM were

statistically analysed and compared using pearson correlation

coefficient. The statistician conducted the statistical analysis

was blind to group allocation until the analysis were completed.

The correlation between PPT and SPADI was strong negative

significant correlation (r = -0.93, p = 0.0001), while the

correlation between PPT with active shoulder abduction ROM

(r = 0.91, p = 0.0001), with passive shoulder abduction ROM

(r = 0.8, p = 0.0001), with active shoulder external rotation

ROM (r = 0.92, p = 0.0001) and with passive shoulder external

rotation ROM (r = 0.94, p = 0.0001) which is strong positive

significant correlation table (3).

Procedures

Localization of a trigger points detection of trigger point

by palpation have obtained an intra- examiner reliability (12);

good inter- examiner reliability ranging from 0.84 to 0.88 and

high Chen et al., (13) supported that the location of the taut

band as identified by the physician in his examination was the

same as that identified in the Magnetic Resonance

Elastography images. The patient was asked to assume supine

position with the arm supported by the plinth. The

Subscapularis trigger points located in the tenderest area in the

posterior axillary wall, which is often located near the most

superomedial aspect of the scapula (14).

A mechanical pressure algometer was used steady and

perpendicular to the identified TrPs. Subjects were instructed

to say "now “when fell discomfort or pain. The mean of 3 trials

was calculated, a 10-s resting period was being allowed

between each trial (15). Pressure thresholds lower than 3 kg are

considered to be abnormally low (16).

Shoulder pain and disability index (SPADIA) used to assess

the shoulder pain and function, it consists of 13 closed

questions (answered with Yes or No). The ratio of the

affirmative answers to the number of applicable items is

multiplied by 100(10). The SPADI demonstrates good

construct validity (17). Higher score means higher pain and

disability (10).

Discussion

The results revealed that there is correlation between

subscapularis trigger point with shoulder function, shoulder

external rotation and abduction in frozen shoulder patients. The

results of present study agreed with Hidalgo-Lozano (19) who

compared 12 patients with unilateral shoulder impingement

and pain in the anterior and posterior aspects of the shoulder

with 10 matched controls were evaluated by an experienced

examiner for the presence of trigger points [TrPs] in the levator

scapulae,

supraspinatus,

infraspinatus,

subscapularis,

pectoralis major, and biceps brachii muscles and compared

with 10 matched controls.

Table 1: Descriptive statistics for the age and BMI of the study group

 _±_S_D

Maximum

Minimum

Age (years)

44.74 ± 6.21

BMI (kg/m²)

24.57 ± 2.36

30.82

19.94

Table 2: The frequency distribution of gender of the study group:

Gender distribution

Females

38 (76%)

50 (100%

Males

12 (24%)

No. (%)

Total

Table 3: Correlation between PPT and all tested variables of the study group

PPT

r value

-0.93

0.91

0.8

p value

0.0001

Sig

SPADI

Active abduction ROM

Passive abduction ROM

Active External rotation

Passive External rotation

0.92

0.94

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Journal of Environmental Treatment Techniques

2020, Volume 8, Issue 4, Pages: 1447-1449

Not surprisingly, patients presented with a significantly

greater number of TrPs, particularly in the supraspinatus,

infraspinatus, and subscapularis muscles, a lower PPT, and

greater pain intensity in several muscles compared with control

subjects. The authors suggested peripheral and central

sensitization mechanisms. The results of present study agreed

with Perez-Palomares et al (20) whos made a descriptive study

to find the correlation between the diagnosis of sub acromial

impingement syndrome, rotator cuff tendonitis, positive

provocation test responses, the existence of active MTrPs and

the results obtained with ultrasonography (US) and Magnetic

Renonance Imaging (MRI). Kuan et al (21) have investigated

the relationship between the presence of muscle TrPs and joint

hypomobility in patients with neck pain, they reported that all

patients exhibited segmental hypo-mobility at C3-C4

zygapophyseal joint and TrPs in the upper trapezius,

sternocleidomastoid, or levator scapulae muscles. There are

several theories that have discussed the relationship between

TrP and joint hypomobility. First, increased tension of the taut

muscular bands associated with a TrP and facilitation of motor

activity can maintain displacement stress on the joint.

Alternatively, it may be that the abnormal sensory input from

the joint hypomobility may reflexively activate TrPs (22).

days, Phys Ther,1998; 78: 160-9.

. Dawson, J., Harris, K. K., Doll, H., Fitzpatrick, R., & Carr, A. A

comparison of the Oxford shoulder score and shoulder pain and

disability index: factor structure in the context of a large

randomized controlled trial. Patient related outcome

measures.2016;7, 195–203.

0. Roy JS et al. Arthritis Rheum .2009,61: 623–632.

11. Michael J, Malachy P, Christopher P and Tyler F (); Reliability of

shoulder range of motion comparing a goniometer to a digital

level; Physiotherapy Theory and Practice, 2010;18:23-33.

2. Shultz SP, Driban JB, Swanik CB. The Evaluation of Electro-

dermal Properties in the Identification of Myofascial Trigger

Points. Arch Phys Med Rehabil,2007; 88:780-4.

3. Chen Q, Bensamoun S, Basford JR, Thompson JM, An K.

Identification and Quantification of Myofascial Taut Bands with

Magnetic Resonance Elastography. Arch Phys Med

Rehabil.2007;88: 1658-61.

14. Ingber RS. Shoulder impingement syndrome in tennis racquetball

players treated with subscapularis myofascial treatment. Arch

Phys Med Reh.2000; 81: 679-82.

5. Fernández-de-las-Peñas C, Alonso-Blanco C, Fernández-Carnero

J, Miangolarra JC. The immediate effect of ischemic compression

technique and transverse friction massage on tenderness of active

and latent myofascial trigger points: a pilot study. J Bodyw Mov

Ther. 2006; 10:3-9.

16.Fischer, A.A., Algometry in diagnosis of musculoskeletal pain and

evaluation of treatment outcome: an update. J Musculoskeletal

Pain 1996;6, 5–33.

7. Breckenridge, J. D., & Mcauley, J. H. Shoulder Pain and Disability

Index (SPADI). Journal of Physiotherapy.2011, 57(3), 197.

8. Kolber, M. J., & Mdt, C. Original research the reliability and

concurrent validity of shoulder mobility measurments using

adigital inclinometer and goniometer.2012; 7(3): 306–313.

Conclusion

Subscapularis trigger points in patients with frozen

shoulder effects shoulder pain, shoulder abduction, and

external rotation.

9.Hidalgo-Lozano A, Fernández-de-las-Peñas C, Alonso-Blanco C,

Ge H-Y, Arendt-Nielsen L, Arroyo-Morales M: Muscle trigger

points and pressure pain hyperalgesia in the shoulder muscles in

Ethical issue

Authors are aware of, and comply with, best practice in

publication ethics specifically with regard to authorship

patients with unilateral shoulder impingement: a blinded,

controlled study. Exp Brain Res. 010;202(4): 915–925 .

(

avoidance of guest authorship), dual submission, manipulation

of figures, competing interests and compliance with policies on

research ethics. Authors adhere to publication requirements

that submitted work is original and has not been published

elsewhere in any language.

0. Perez-Palomares, S., Oliván-Blázquez, B., Arnal-Burró, A. M.,

Mayoral-Del Moral, O., Gaspar-Calvo, E., De-La-Torre-

Beldarraín, M. L., Romo-Calvo, L.Contributions of myofascial

pain in diagnosis and treatment of shoulder pain. A randomized

control trial. BMC Musculoskeletal Disorders.2009, 10(1), 1–7.

1. Kuan TS, Wu CT, Chen S, Chen JT, Hong CZ. Manipulation of the

cervical spine to release pain and tightness caused by myofascial

trigger points [Abstract] Arch Phys Med Rehabil. 1997;78:1042.

Competing interests

The authors declare that there is no conflict of interest that

would prejudice the impartiality of this scientific work.

22. Fernández-de-las-Peñas Interaction between Trigger Points and

Joint Hypomobilityꢀ: A Clinical Perspective. 17(2), 74–77.

Authors’ contribution

All authors of this study have a complete contribution for

data collection, data analyses and manuscript writing.

References

. Zuckerman, J. D., & Rokito, A. Frozen shoulder: a consensus

definition. Journal of shoulder and elbow surgery / American

Shoulder and Elbow Surgeons. 2011; 20(2): 322–5.

. Nambi, G., & Kamal, W. Additional effect of Trigger point

therapy and Myo fascial release on second stage Frozen

Shoulder

among

industrial

workers.

Sanamed.2017;12(2),93.

. David G,Simsons:frozen shoulder workbook ;trigger point therapy

for overcoming pain and regaining range of motion .2016;8-25.

. Alvarez, D. J., & Rockwell, P. G. Trigger Points: Diagnosis and

Management. 2012.

. Niel-Asher, S. The Concise Book of Trigger Points (Revised

Edition). In The Concise Book of Trigger Points. 2008.

. World Medical Association. WMA Declaration of Helsinkiethical

principles for medical research involving human

subjects 2015.

. Antonaci F, Sand T, Lucas GA. Pressure algometry in healthy

subjects: inter-examiner variability. Scand J Rehabil Med.1998;

0:3-

Nussbaum EL, Downes L .Reliability of clinical pressure-

pain algometric measurements obtained on consecutive

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