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Table of Contents
Year : 2022  |  Volume : 4  |  Issue : 2  |  Page : 159-163

Case study: Rehabilitation of a painful shoulder – A perspective biomechanical approach

1 Department of Sports Sciences, JSS College of Physiotherapy, Mysore, Karnataka, India
2 Department of Musculoskeletal and Sports Physiotherapy, Brainware School of Medical and Allied Health Sciences, Brainware University, Barasat, West Bengal, India
3 Department of Musculoskeletal and Sports Physiotherapy, JSS College of Physiotherapy, Mysore, Karnataka, India

Date of Submission30-Mar-2022
Date of Decision16-Nov-2022
Date of Acceptance16-Dec-2022
Date of Web Publication19-Jan-2023

Correspondence Address:
Dr. V Vijay Samuel Raj
Department of Sport Science, JSS College of Physiotherapy, Mg Road, Mysore - 570 004, Karnataka
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijptr.ijptr_43_22

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The deltoid muscle is often forgotten when it comes to the evaluation and planning of treatment in shoulder conditions. Shoulder dysfunction, rotator cuff tendinopathy, and frozen shoulder are the conditions that affect functioning in major cases. The study involved an exploration of possible causes of dysfunction, especially pain and overhead activities. The patient presented with chronic pain and decreased shoulder function. A suitable shoulder rehabilitation program was designed keeping the deltoid muscle denervation into consideration. The shoulder pain, range of motion, strength, and function were evaluated at the baseline and the end of 6 weeks. The results were correlated and explored to identify the involvement of the deltoid muscle. The study showed a positive test of deltoid muscle involvement, which was identified through the strength-duration curve. There was a clinically significant improvement observed in the patients' function. Hence, the study hypothesized that along with scapular stabilization, it is important to consider deltoid equally during the assessment and treatment plan in shoulder rehabilitation program.

Keywords: Axillary nerve, deltoid, physiotherapy, rehabilitation, shoulder dysfunction, shoulder pain

How to cite this article:
Raj V V, Ukil KD, Shetty A. Case study: Rehabilitation of a painful shoulder – A perspective biomechanical approach. Indian J Phys Ther Res 2022;4:159-63

How to cite this URL:
Raj V V, Ukil KD, Shetty A. Case study: Rehabilitation of a painful shoulder – A perspective biomechanical approach. Indian J Phys Ther Res [serial online] 2022 [cited 2023 Jun 6];4:159-63. Available from: https://www.ijptr.org/text.asp?2022/4/2/159/368056

  Introduction Top

The shoulder complex is an intricately designed combination of the glenohumeral joint, sternoclavicular joint, acromioclavicular joint, and scapulothoracic joint formed by the clavicle, scapula, and humerus. Shoulder articular structures are intended primarily for mobility, allowing for a wide range of motion (ROM).[1] The freedom of movement at the shoulder complex requires both mobility and stability which rely on both static and dynamic stabilization.[2] Dynamic stabilization results from a unique functional balance between mobility and stability through forces by the muscles that rely on dynamic muscular control rather than passive forces. The shoulder complex, muscles provide a stable base for the upper limb movements, it is important that the stability of scapula is essential to carry out an efficient function. When there is a loss of stabilization factors due to various reasons, the shoulder complex is susceptible to instability and dysfunction.

The common nerves that are involved in the shoulder are the axillary, long thoracic, and suprascapular and musculoskeletal nerves. The axillary nerve (AN) supplies the deltoid muscle, musculoskeletal nerve supplies the biceps, and may be entrapped or diseased. AN injury may present with axillary neuropathies caused due to various traumatic and compression injuries, also weakness of deltoid may be causative due to pathologies including subdeltoid bursa, acromion, and lateral clavicle.[3] Men are prone to AN injury than women at the ratio of 3:1.[4] Among the shoulder injuries, 9%–65% is AN injury.

The deltoid weakness can contribute to active loss of shoulder abduction, flexion, and extension and may be also caused due to AN injury, and caused due to anterior inferior dislocation, fracture, and fall on outstretched arm. The free portion of AN can be elongated due to displacement of the head of the humerus and may result in the avulsion of AN.[5] A special consideration needs to be made on the evaluation and functional diagnosis of shoulder dysfunction. The stability and mobility factors and ratio of contribution during upper limb function have to be considered in the assessment and plan of care during shoulder rehabilitation. This manuscript presents the interesting case study with an aim to present the importance of biomechanical evaluation and treatment, emphasizing on the evaluation of the auxiliary nerve involvement.

  Case Report Top

The client was a 63-year-old adult male, who visited the physiotherapy department at a tertiary hospital with complaints of pain at the left shoulder and arm for the past 6 months. He reported 1st episode of injury during performing sumo squat, which included squats with wider base and holding a kettlebell and also later during bicep curl of 5 kg and triceps curls of 5 kg. The pain aggravated on any of the weightlifting activities since then. He consulted the orthopedic surgeon and diagnosed with partial width tear of the supraspinatus, subacromial impingement of rotator cuff, subdeltoid bursitis, and bicipital tenosynovitis. He was prescribed analgesics, advised to rest for 10 days, and referred to physiotherapy. He was treated with joint mobilization emphasizing on inferior glides with stretching of trapezius, and strengthening, and went for acupuncture. There was a 60%–70% reduction in the Visual Analog Scale (VAS) after treatment, but with a reoccurrence of pain intermittently. Three months later, during his trip abroad, with no specific reason mentioned, the pain increased in the night, for which he took therapy for 2 days from a joint specialist, where he found symptomatic relieve. The second episode occurred after lifting a suitcase of 23 kg to place it at the high head plank, which gave sudden sharp shooting pain to the patient at the left shoulder, which disabled him from lifting any weight. He had his visit to the department after this incident.

The sumo squat included standing with wide feet at shoulder width apart holding a kettlebell with both arms in front. Normally, the squat would include dropping the hips back and down, as sitting in a chair, allowing the kettlebell to swing down in between the legs, one would use the knee and hip to swing the kettlebell up and not the shoulders or one's arms. Probably, altered biomechanics would have been followed by the patient using more of his arms and shoulders, leading to a hypothesis of the shoulder muscles involvement leading to strain or AN injury.

The subjective and objective data were collected and presented with clinical reasoning form using a visual analysis. The data were plotted using Microsoft Office Excel software at baseline, before intervention and after 4 weeks of planned exercise program, and 6 weeks for discharge. Written consent was obtained from the client and the physiotherapy plan was clearly explained in his own language.

Patient evaluation and treatment planning

The client was interviewed with detailed subjective evaluation before starting of the exercise program. The client could not perform activities of daily living involving reach to the back by the left hand, and he complained about the difficulty in overhead activities and pain limiting the function. The initial evaluation of pain assessment, postural deformity, girth, muscle strength, and ROM evaluation was recorded and documented. The sensation over the neck and upper limb was intact. In the outcome measure, the Shoulder Pain and Disability Index (SPADI) of 71.53% was reported. In pain level, initial intensity of the pain was VAS 8 out of 10, the characteristics were chronic dull aching and most of the time patient experienced pain in the morning time, aggravating factor was due to stretch, weight lifting, sleeping on the affected side, and relieving factors were rest and heat application.

On observation, muscle atrophy in infraspinatus, supraspinatus, deltoid, triceps, and biceps was noticed. The posture assessment on the postural grid depicted a protracted shoulder, elevated shoulder on the left side, and winging of the scapula. The shoulder ROM during flexion, extension, abduction, and external and internal rotation was limited [Table 1], with a firm end feel, pain onset (P1) followed by resistance limit (R2). The muscle strength and girth measurements were also taken shown in the table and abnormal glenohumeral rhythm (scapular dyskinesia) was noticed. Special tests for the shoulder were done to identify the underlying pathology. Empty can test, superior and inferior scratch test, Neer impingement test, speed's test, and Yergason's test, all were considered positive, these were in turn the interpretation of patient and the impingement of supraspinatus and biceps were possibly confirmed, with joint capsule involvement. Correlating the finding of special tests and kinetics, possibly a compression at the quadrilateral space may be considered for further evaluation.[6],[7] The presenting symptoms of the patient were night pain and weakness in the shoulder–glenohumeral abduction and external rotator, without numbness to the lateral shoulder area. Thus, leading to a hypothesis of the involvement of the middle deltoid and the AN, this may be caused due to primary shoulder impingement syndrome, caused due to faulty shoulder position.
Table 1: Strength of muscles and joint range of motion

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Baseline tests and follow-up were conducted before the start of the exercise program. The tests are joint ROM, muscle strength, VAS, and strength-duration curve (SDC). The follow-up tests were conducted every week and 4 weeks after to check the improvement, and with obtained results, the exercise program was changed for consecutive sessions based on the assessment using the same test methods and finally at 6 weeks for discharge. A minimal clinically important difference (MCID) for ROM of ≥9° was considered. The shoulder function was assessed using SPADI, considering a MCID of 8–13 points.[8] The muscle girth was assessed using a standard flexible inch tape and measured in centimeter (cm).[9]

Rehabilitation program

The exercise program was composed of 6 weeks [Annexure 1], planned in five phases, which included the baseline tests and every week follow-up tests. To reduce the pain at left shoulder ultrasound therapy (UST), faradic muscle stimulation for supraspinatus, biceps, and anterior and middle deltoid 30 contractions [Annexure 1].

Visual Analog Scale

The level of subjective pain was measured using VAS when the shoulder joint was moved, with 10 as the highest level of pain. Pain at the shoulder joint before the exercise was 8, and the pain level reduced to 6 in 4 days and to 4 in 2 weeks at the maximum joint range.

Muscle girth, strength, and function

The girth measurement showed an improvement with a difference of 4.5 cm in the left arm girth. Similarly, at left forearm showed a difference of 1 cm. The significant improvement in muscle strength was noted in shoulder flexors (anterior fibers of deltoid, long head of biceps, and supraspinatus) with a difference of 10 lbs and similarly in biceps muscle with a difference of 19 lbs. However, the strength of shoulder extensors, abductors, internal rotators, and external rotators showed improvement, it was negligible as the difference was <6 lbs. The results of the strength measured by handheld dynamometer are depicted in [Table 1]. Improvement in function was achieved; SPADI outcome was noted at 71.53% in the baseline and 86.55% in the posttest, with a difference of improvement of 15%, with difference score of 40 points, which was far above the MCID.

The measurements were taken in the following order: shoulder flexion, abduction, internal rotation, and external rotation. Joint motion observed an increased range in all movements with an evident increase in shoulder internal and external rotation. The ROM improvement in flexion and abduction can be ignored considering the MCID and errors. The results of the ROM of shoulder joint are shown in [Table 1].

Strength duration curve

The SDC responses for the biceps muscle (AN) showed abnormal chronaxie (2.2 ms), with the curve representing a compression, showing a minimal kink [Figure 1]. The posttest responses recorded a normal chronaxie (0.38 ms) representing a normal curve. An evident improvement in the strength response was observed depicting that the nerve function may be restored.
Figure 1: SDC of axillary nerve (deltoids). SDC: Strength duration curve

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The study was conducted in five phases. In the first phase, the treatment plan was made after evaluating the patient. In the second phase, preliminary tests were conducted. In the third phase, the exercise protocol was programmed. In the fourth phase, reevaluation was done, and in the fifth phase redesigning of exercise program over 6 weeks, each of the sessions lasted for 1 h.

  Discussion Top

Historically, the assessment of musculoskeletal problems in the shoulder joint has been based on the premise that it is possible to isolate the individual structure at fault. In the differential diagnosis of shoulder dysfunction, it is essential to rule out the origin of pain, in this case, the evaluation findings hypothesized that it might be due to AN pathology involving the deltoid muscle. In this case, postexercise, there was a lag in the shoulder flexor strength, in contrary to the biceps brachii muscle showing an excellent improvement in strength, when compared with the unaffected side. This leads to the confirmation of the anterior deltoid muscle involvement. This study further concludes that in spite of strong improvement in the deltoid group of muscles, the strength was not achieved to match the unaffected side. Exercise programs of longer duration exceeding 6 weeks may be necessary to achieve actual strength with change in the resistance training programs.[10] Patient reported that the sumo squat with kettlebell exercises caused the first episode, this supports with the possibilities of abnormal kinematics and kinetics[11] of the shoulder and scapula, leading to AN injury. This study emphasizes, the biomechanical evaluation including movement analysis may aid in functional decision-making and planning an appropriate physiotherapy intervention. This may be evidently followed in sports injury management. Many times, the deltoid muscle is ignored during the shoulder evaluation. However, the shoulder stabilizers involving the scapula stability play an essential function during static and dynamic activities, it is necessary to consider the deltoid along with the scapular muscles during the assessment of shoulder dysfunction and plan an appropriate plan of care. In this study, the patients, glenohumeral accessory movements (glides) were optimal, but pain limiting the movement, and due to the reason passive mobilization techniques were not delivered. There was a significant improvement observed in the patients' function, both subjectively and objectively. The parameters such as SPADI, muscle strength, and muscle girth measurements have shown significant clinical improvement in recovery. The patient was enthusiastic and cooperative throughout the treatment session, and there were no difficulties observed by the patient to follow the exercise protocol.

  Conclusion Top

The study showed a positive test of deltoid muscle involvement, which was identified through the strength-duration curve. There was a clinically significant improvement observed in the patients' function. Hence, the study hypothesized that along with scapular stabilization, it is important to consider deltoid equally during assessment and treatment plan in shoulder rehabilitation program.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  Annexure 1 Top

Shoulder Rehabilitation Protocol:

  1. Passive and active stretching of pectorals and biceps muscle
  2. Faradic Stimulation – Deltoid inhibition techniques – Intermittent 100 Hz, 1 ms pulse duration, rest time 5–10 s. 20–30 contractions
  3. UST (1 Mhz, pulsed 1:1, 0.8 W/cm2, 4–6 min) calculated based on the standard operating procedure of the department of physiotherapy, and treatment calculation chart. (Watson, T. (2002). “Ultrasound Dose Calculations“ In Touch 101;14-17)
  4. Strengthening exercises comprised.

    1. Muscle setting exercises (isometrics)
    2. Resistance exercise with resistance band and dumbbells for shoulder flexors and abductors (10 rep × 3 sets) each in supine lying
    3. Horizontal abduction was planned to improve eccentric contraction of retractors and active stretching of pectorals (10reps × 3 sets)
    4. Retractor strengthening using resistance band (10 reps × 3 sets)
    5. Bicep curl-ups using 60%–80% 1 RM graded increment using dumbbells (10 reps × 3 sets)
    6. Triceps strengthening using resistance band (10 reps × 3 sets)

  5. Home exercise program with plans to improve the retractor strength and shoulder mobility and strength was planned for 5 days/week
  6. Safe lifting techniques and ergonomic measures were advised.

  References Top

Miniato MA, Varacallo M. Anatomy, shoulder and upper limb, shoulder. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536933/. [Last updated on 2019 Mar 08].  Back to cited text no. 1
Veeger HE, van der Helm FC. Shoulder function: The perfect compromise between mobility and stability. J Biomech 2007;40:2119-29.  Back to cited text no. 2
Moser T, Lecours J, Michaud J, Bureau NJ, Guillin R, Cardinal É. The deltoid, a forgotten muscle of the shoulder. Skeletal Radiol 2013;42:1361-75.  Back to cited text no. 3
Tessler J, Talati R. Axillary nerve injury. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539895/. [Last updated on 2020 Jan 22].  Back to cited text no. 4
Hangge PT, Breen I, Albadawi H, Knuttinen MG, Naidu SG, Oklu R. Quadrilateral space syndrome: Diagnosis and clinical management. J Clin Med 2018;7:86.  Back to cited text no. 5
Steinmann SP, Moran EA. Axillary nerve injury: Diagnosis and treatment. J Am Acad Orthop Surg 2001;9:328-35.  Back to cited text no. 6
Kolber MJ, Hanney WJ. The reliability, minimal detectable change and construct validity of a clinical measurement for identifying posterior shoulder tightness. N Am J Sports Phys Ther 2010;5:208-19.  Back to cited text no. 7
Roy JS, MacDermid JC, Woodhouse LJ. Measuring shoulder function: A systematic review of four questionnaires. Arthritis Rheum 2009;61:623-32.  Back to cited text no. 8
Abizanda P, Navarro JL, García-Tomás MI, López-Jiménez E, Martínez-Sánchez E, Paterna G. Validity and usefulness of hand-held dynamometry for measuring muscle strength in community-dwelling older persons. Arch Gerontol Geriatr 2012;54:21-7.  Back to cited text no. 9
Thomas MH, Burns SP. Increasing lean mass and strength: A comparison of high frequency strength training to lower frequency strength training. Int J Exerc Sci 2016;9:159-67.  Back to cited text no. 10
Kettlebell and Medicine Ball Exercises Human Kinetics. Available from: https://us.humankinetics.com/blogs/excerpt/kettlebell-and-medicine-ball-exercises. [Last accessed on 2022 Dec 14].  Back to cited text no. 11


  [Figure 1]

  [Table 1]


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