Rehabilitation of the Shoulder Subluxation Based on Ultrasonographic Findings among Post Stroke Subjects: A Case Series
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.329613
Source of Support: None, Conflict of Interest: None
Keywords: Acromion-greater tuberosity, cerebrovascular accident, Fugl-Meyer assessment, glenohumeral, hemiparesis
Shoulder subluxation, partial dislocation of the glenohumeral joint, usually exhibited in form of inferior disarrangement among poststroke subjects. Up to three-fourths of the poststroke survivors may experience the shoulder subluxation during the recovery process., The multifactorial pathomechanics for this preventable complication ranges from poor motor control to mal-handling., Consequent to the development of the subluxation, the motor and functional recovery of the paretic limb gets compromised. In addition to this, the disabling shoulder pain may also be experienced, affecting the overall quality of life., Thus, the subluxation multifold the post stroke impairment and increases the challenges of rehabilitation.
Shoulder girdle comprises multiple joints (glenohumeral, acromioclavicular, and sternoclavicular) and active (muscles) and passive (capsule, ligaments, bursae, and labrum) structures. All components play an important role for dynamic and static stability.,Any derangement of the skeletal structure would inevitably affect the integrity and function of other surrounding tissues.
Poststroke, the paresis of supraspinatus and posterior deltoid could be the key causative factor for the shoulder instability. During flaccid stage the muscles, capsule, and ligaments experience overstretching that may also lead to the subluxation. In addition to this, the spasticity of the certain shoulder muscles inducing muscle imbalance could also be the related factor.,, Extremes of shoulder elevation passively performed by the therapist or caretaker and gravitational pull are also the precipitating factor for maligning the shoulder after stroke., In addition to this, the subluxed hemiparetic shoulder has been found to be associated with soft tissue injury such as impingement, tendonitis, and tear as well as pain., However, not all subjects with the subluxation experience the shoulder pain., Thus, a subluxation involves various issues ranging from joint to soft tissue that may not be discerned by clinical evaluation methods.
The assessment of shoulder subluxation has been evolving since decades. Fingerbreadth palpation method (clinical) and X-ray (radiological) are the commonly used procedures to measure the magnitude of the subluxation. Fingerbreadth method subjectively provides three levels of the subluxation, whereas the X-ray measures the asymmetry in millimeters (mm) in relation to the unaffected shoulder. However, both of these methods do not assess the soft tissue involvement. Musculoskeletal ultrasonography is another method, which has been utilized to examine the shoulder subluxation (in mm) as well as the soft tissue status. The sonography has been found to be a reliable, valid, and most comprehensive measure, strongly recommended for the assessment of the subluxed shoulder in stroke.,,,,,
Poststroke, shoulder subluxation is an avoidable complication; however, if once occurs the management usually becomes a challenge.,, Array of techniques such as orthosis and functional electrical stimulation have been investigated to rehabilitate the subluxed shoulder.,,, These methods are based on alleviating the pathomechanics such as providing an antigravity upward pull or strengthening the weak muscles. Shoulder orthosis provides a support and upward directed force for the arm toward the glenoid cavity. The objective is to normalize the glenohumeral joint space; however, the orthosis is effective till it is being worn. The functional electrical stimulation is also being applied to augment the paretic muscles such as supraspinatus; however, the technique is effective in acute stroke. Most of these methods were not found to be robustly evident for reducing the subluxation. Further, none of the study has considered the sonography as an assessment method for objective evaluation of the subluxation and associated soft tissue involvement.
Currently, the management of subluxation is based on the clinical assessment and biomechanical principles. No study has been found investigating the effect of intervention utilizing the sonographic findings. It is hypothesized that the sonographic-based rehabilitation of the subluxation would prevent further complication and enhances the motor recovery. The objective of the present study was to determine the effect of rehabilitation protocol based on the sonographic findings of the subluxed shoulder. The protocol was evaluated for the reduction of the subluxation, soft tissue involvement, shoulder pain, and upper limb recovery.
The present case series was carried out in a national level rehabilitation institute located in an urban north Indian city. The investigation was endorsed by the institutional ethics committee of Pandit Deendayal Upadhyaya National Institute for Persons with Physical Disabilities, New Delhi, India. The study followed the preferred reporting of case series in surgery (PROCESS) guidelines. All the study participants were briefed and provided written information about the study protocol. The eligible subjects were asked to participate voluntarily and to sign the informed consent form. The participants were conveniently recruited considering the following inclusion criteria: (i) poststroke hemiparesis due to unilateral stroke, (ii) paresis of either right or left side, (iv) adult stroke, and (v) any grade of subluxation (clinically assessed by fingerbreadth method). However, the subjects were excluded if they had any of the following characteristics: (i) any other associated neurological disorder, (ii) severe cognitive and perceptual deficits,(iii) cardiovascular instability, and (iv) any other musculoskeletal disorder affecting the shoulder.
A prospective, single center case series of nonconsecutively selected eight subjects.
Fingerbreadth palpation method
The method is used to palpate the space between the acromion process of the scapula and the head of humerus using the finger. The subluxation is graded on three levels: 1: minimal (finger partially inserted); 2: moderate (finger completely inserted); or 3: severe (space available after inserting the finger). The assessment technique has been found to be a reliable and valid measure., Further, the method has been found to be used in the stroke studies.,
The ultrasonography of the shoulder has been recommended as a diagnostic tool to quantify the degree of shoulder subluxation in poststroke hemiparesis. The method utilizes the measurement of acromion-greater tuberosity (AGT) distance (mm) for the assessment of subluxation. The asymmetry was further analyzed by comparing the same with the unaffected shoulder. The measurements of AGT distance demonstrated good intrarater and interrater reliability among healthy individuals. The measurements of AGT distance demonstrated good intrarater and interrater reliability among stroke subjects.,,, Further, the ultrasonography also provides the status of musculoskeletal including soft tissue alteration associated with the subluxation of the shoulder among stroke subjects.
In the present study, high-frequency two-dimensional grey color Doppler imaging–assisted ultrasound [GE LOGIQ S 8, Linear Array probe ML6-15-D (4-15MHz)] was carried out for the shoulder joints. The forearm was pronated and supported on a pillow, with elbow flexed at 90 degrees. The subject was sitting with both feet touching the floor. Static and dynamic real-time imaging was performed throughout the physiological range of motion in orthogonal planes. Annexure I provides the detail parameter utilized for the sonographic assessment. The AGT difference of ≥2mm was considered as a reference value for the presence of shoulder subluxation.
The Fugl-Meyer's assessment is the most common and recommended measure to quantify the upper limb recovery in stroke., FMA hierarchically measures the motor ability as per the recovery pattern commonly observed among the stroke survivors. In the present study, only the upper extremity section of FMA (FMA-UE) was used. The section comprises 33 items of reflexive, synergistic, and mixed/out-ofsynergy movements. The motor performance is scored on 3-point ordinal scale (0: no performance; 1: partial performance; and 2: complete performance). The total FMA-UE score is 66. It has demonstrated high reliability and validity to assess motor recovery among stroke subjects.,,,
In the present study, the guidelines provided by Sullivan KJ et al. (2011) were utilized for applying the FMA-UE.
Visual analog scale
The visual analog scale (VAS) is an economical, simple, and reliable method for measuring pain intensity. The pain is quantified by marking a vertical line on 10-cm line, 0 indicates no pain to 10 exhibits worst pain. The measure has been used to score subluxation-related shoulder pain in stroke.,
All the potential subjects were clinically assessed for the presence of the subluxation using fingerbreadth method. The subjects who exhibited the subluxation were further undergone the preassessment using other outcome measures including the shoulder ultrasonography.
Based on the ultrasonographic findings, rehabilitation technique such as motor therapy, posture training, and surgical referral has been provided to the study participants.[Figure 1] provides a guideline for the specific intervention as per the ultrasonographic findings. The management techniques utilized in the present study were based on the principles of biomechanics, kinesiology, and muscle reeducation., The shoulder support was provided to counter the gravitational pull and to augment the joint stability during therapeutic activities and daily tasks. Additionally, physical agent modalities (deep thermal) were also incorporated to alleviate pain and enhance soft tissue healing., Postassessment was also carried out for the participants who received rehabilitation intervention. The intervention regime was provided for a period of 3 months.
All the enrolled subjects completed the protocol of the study. The age range of the participants was 35 to 76 years with 7 men and 1 woman. The numbers of ischemic and hemorrhagic stroke were four each. Further, there were four right- and four left-sided hemiparetic subjects. The demographic detail of the study participants is provided in [Table 1]. The subluxation grade ranged from 1 to 3 among the subjects (3 subjects: grade 1; 3 subjects: grade 2; and 2 subjects: grade 3). The ultrasonographic findings exhibited AGT difference (affected vs normal) ranged from 1 to 10 mm. [Figure 2] shows the AGT asymmetry between the normal and affected shoulders on a sonographic scan.
In addition to this, soft tissue involvement ranging effusion to tear was also demonstrated. [Table 2] shows the detail of the ultrasonographic findings and other prepost assessment. Only two patients had shoulder pain with VAS of 7 to 10. The subjects (n = 02) with grade 1 subluxation exhibited AGT difference of 3 to 4 mm and atrophy of the supraspinatus and deltoid. One of the subject with clinical subluxation of grade demonstrated only 1 mm AGT asymmetry, which was not considered as a radiological subluxation. The participants with grade 2 subluxation (n = 3) showed AGT difference of 6 to 9 mm, atrophy of trapezius, supraspinatus, and deltoid, and soft tissue and joint effusion. The subjects (n = 02) with grade 3 subluxation had 8 to 10 mm of AGT difference, tear of either capsule or supraspinatus along with the muscle atrophy. Based on the sonographic findings subjects have been provided intervention as mentioned in [Table 3]. Post intervention, the participants (n = 6) showed 1 to 6 mm of reduction of AGT distance in addition to the reduction of atrophy and soft tissue or joint effusion.
To our knowledge, the present case series is a first study that focused on the rehabilitation of poststroke subluxation based on the ultrasonographic findings of the affected shoulder. In this study, the sonography of the subluxed shoulder exhibited AGT asymmetry to soft tissue tear. The findings provided clear direction for the further management. For instance, if the sonography showed atrophy of the deltoid, shoulder flexion, and abduction were trained. The postassessment further confirms the minute reduction of the AGT difference and change in soft tissue status. In case of soft tissue tear, appropriate referral was also made. It is understood that in the absence of sonography, the application of rehabilitation method would be blurred. Such approach may result into further deterioration of the related joint alignment and injury to the tissues.
The sonographic findings of the present study are in accordance with the investigation of Huang et al. (2012). They observed tendonitis of supraspinatus infraspinatus, subscapularis and biceps muscles, as well as tear of the supraspinatus muscle of the subluxed shoulder. This was the only study found exploring the involvement of various soft tissues in the subluxed shoulder. However, unlike the present case series, Huang et al. study was on acute stroke. Other sonographic investigations have also been carried out for the hemiparetic shoulder. These studies indicated that the affected shoulders have soft tissue involvement irrespective of the subluxation.,,
The findings such as tendonitis, bursitis, and inflammation can be elaborated by ultrasonography. These issues may be managed by physical agent modalities. It is understood that such management would allow quality movement training, augmenting reduction of the subluxation.
In the present study, the AGT difference between the unaffected and affected shoulder ranged between 3 to 10 mm. The observed difference is in accordance with the study of Kumar et al. (2011), in which the mean difference between the shoulders was 3 to 4 ± 6 mm. Only one subject of the present study exhibited the AGT difference of 1mm in spite of clinical presence of grade I subluxation. This could be attributed to the 3-point grading method for fingerbreadth method used in the study. Whereas in the study that established the cutoff value of ≥ 2 mm for the subluxation utilized the 5-point grading system. All other participant of the present study exhibited the cutoff value of 2 mm for the AGT difference.
Atrophy of the shoulder muscles such as deltoid and surpraspinatus were also observed in the present study. Changes in the muscle structure and function due to disuse atrophy have scarcely been focused in stroke assessment and management., Further, the muscle atrophy has not been reported in the sonographic study of the subluxed shoulder among acute stroke subject. The variation could be attributed to the chronicity of the participants in the present study. Further, the motor training of the affected muscles led to the reduction of atrophy in this study. The favorable change in muscle atrophy because of the motor intervention has been established at the molecular level. Additionally, the strengthening of paretic shoulder including scapular muscles has been recommended among poststroke subjects. Movements such as shoulder flexion and abduction have been emphasized in the present study. The stabilizer role of the deltoid muscle is crucial for the malaligned shoulder. In addition to this, strengthening of the deltoid may be more beneficial than other shoulder muscles for reducing the subluxation.
Various aspect of subluxation management such as posture, pain, and movement has been recommended in the literature. The correction of posture has also been intervened in the present study to augment the favorable position of the shoulder. The poor spinal posture affects scapular kinematic and muscle force production during the shoulder movements., Further, postures with reduced base of support such as standing may recruit greater activity of the shoulder girdle muscles that in turn enhances reduction of the subluxation. There are various types of shoulder support used in management of the subluxation. However, strong consensus and evidence regarding the use of specific orthosis is lacking in the clinical practice. In the present study, considering the standard practice at the site of study, the neoprene cuff type support was used.
Poststroke, the shoulder subluxation is considered to be an important predictor of the upper limb recovery. The subluxation is more common among the severely paretic patients in comparison to the subjects with mild paresis. The subluxation has been found to be related with the motor recovery in acute stroke; the reduction of subluxation would depend upon the substantial upper limb recovery. However, the same may not be true for the situation where the subluxation was caused by the external factors. The presence of subluxation would rather hamper the motor recovery and cause certain complications. If the subluxation occurs and the causative factors remain persist, it is understood that the soft tissues such as rotator cuff muscles are prone to get injured. Although the abnormal sonographic findings may be considered as undesirable factor for the motor recovery, a study for the shoulder pain indicated no relation between the findings and recovery.
Ultrasonography has been an emerging for poststroke subluxation. However, magnetic resonanceimaging (MRI) has been suggested as a better option than the assessor-dependent sonography. MRI study among poststroke subjects with shoulder pain also exhibited abnormalities such as rotator cuff tear and tendinopathies.
In the present study, postsurgical follow-up could not be conducted. All the subjects were at chronic phase of stroke (>6 months of onset). In addition to this, the actual time of occurrence of subluxation and various causative or risk factors might not have discerned in the chronic stage.
Further sonographic-based study incorporating functional electrical stimulation may be conducted for the management of the subluxed shoulder in the acute stage. Other physical agent modalities for managing the soft tissue inflammation may also be considered in the future studies. The present case series was a pilot study, conducted to ascertain a framework for the subluxation management based on the sonographic findings. A randomized controlled trial is further warranted to validate the findings of this study.
The ultrasonographic evaluation explored objective measurement as well as involved soft tissues in poststroke shoulder subluxation. The issues such as complete tear of supraspinatus, tendinitis, joint effusion, could be associated with subluxation; however, cannot be identified and managed without ultrasonographic evaluation. The rehabilitation approach based on sonographic findings was successful and provided a clear direction for the management. Further, the reason for the failure of subluxation reduction could also be discerned by the sonography. Referral for the orthopedic surgical intervention, which is usually ignored in the impairment, could also be emphasized by the assessment.
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Conflicts of interest
There are no conflicts of interest.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]