cerebrovascular stroke ( cvs ) is a neurologic event related to diseases of the cerebral 
 circulation . cvs has been shown to be a major cause of death and disability in all 
 communities . according to the american stroke association , about 87% of strokes are 
 ischemic , and the remaining 13% are hemorrhagic1 , 
 2 . stroke survivors can suffer some 
 neurological impairments , such as hemiparesis , communication disorders , cognitive deficits , 
 or disorders in visuospatial perception3 , 4 . hemiparesis of the upper limb is conceivably the most serious impairment and most in need 
 of rehabilitation . population - based studies indicated that 7388% of first - time strokes 
 result in an acute hemiparesis of the upper and/or lower limbs5 , 6 . the impact of upper limb 
 impairments on disability and health is very obvious7 , 
 8 . however , limited attention has been 
 given to upper - extremity rehabilitation after stroke , and generally functional recovery of 
 the upper limb and hand is limited compared with that of lower extremities9 , 10 . a scapular stabilization exercise program performed over a 4-week period resulted in 
 improvement of upper limb function in an group of 11 chronic hemiparetic patients11 . even in patients with acute stroke , 
 passive range of motion exercises can improve the function of upper extremities12 . hemiparetic patients have an altered postural alignment in standing compared with subjects 
 without neurological deficits13 . postural 
 alignment is defined as the relationship of body parts to the line of the center of gravity 
 ( cog ) . maintaining postural stability is a complex process that is an essential prerequisite 
 for the advanced stages of motor control including ; controlled mobility and skilled 
 activity14 . structures in the 
 brainstem , the red nucleus , pontine and medullary reticular formations , vestibular nuclei , 
 and superior colliculus , are responsible for the control of posture and spatial 
 orientation15 . applications of constraint - induced movement therapy ( cimt ) for upper - extremity recovery are 
 promising in chronic and acute stroke16 , 17 , and is less promising in subacute 
 stroke18 . other studies showed that 
 repetitive training of isolated movements against resistance for 15 minutes twice a day for 
 4 weeks improved the motor function of paretic hands in subacute stroke19 . a systematic review with meta - analysis of randomized 
 trials of strengthening interventions in stroke patients concluded that strengthening 
 interventions increase strength , improve activity , and do not increase spasticity20 . the purpose of this study was to investigate the effect of strengthening exercises for 
 shoulder girdle muscles , particularly the scapular muscles , on lateral trunk deviation in 
 both static positions and functional activities in hemiparetic patients after stroke . this study was conducted in the outpatient clinic of the faculty of physical therapy , cairo 
 university , between december 2010 and january 2012 . the study included 30 patients with 
 cerebrovascular stroke , either ischemic or hemorrhagic , based on a clinical assessment , ct 
 scan , and/or mri . all 
 patients provided a written informed consent prior to participation in the study . clinical evaluation of the patients included neurological , musculoskeletal , and perceptual 
 assessments using the line cancellation test . shoulder stability was examined by palpating 
 the space between the acromion process and humeral head . the study included pain - free hemiparetic patients with scapular asymmetry , dropped 
 shoulder , and spinal lateral deviation towards the affected side in a sitting position . the 
 inclusion criteria were age 4560 years , disease duration 612 months , good sitting balance , 
 and good voluntary motor control of at least stage 4 according to brunnstrom s scale . the 
 exclusion criteria included balance disturbance due to other causes , stroke with unilateral 
 neglect , sensory manifestations , uncorrected visual impairment , spinal deformities , and 
 orthopedic disorders of the lower limbs or back . participants were randomly divided into two 
 equal groups , a study group and control group . . shoulder girdle muscle strength : an isokinetic dynamometer ( biodex system 3 , biodex 
 medical systems , shirley , ny , usa ) was used to assess the peak torque of shoulder abductors 
 and external rotators . during the test , the patient sat in the biodex system s chair . for 
 each muscle group , no 
 verbal encouragement or other reinforcement was given to any patient during the actual 
 test . scapular muscle peak force measurements : a handheld dynamometer ( hhd ) ( lafeyette manual 
 muscle test system , model number 01163 , lafayette instrument company , lafayette in , usa ) was 
 used to measure the isometric peak force ( kg ) of the supraspinatus , upper trapezius , and 
 serratus anterior muscles . three trials were performed for each muscle with a rest period of 
 1520 seconds so that declines in strength across trials , due to fatigue , could be avoided . the supraspinatus and upper trapezius muscle peak forces were recorded from a sitting 
 position on a stool with the hips and knees at 90 flexion and the feet supported . postural assessment with the coreldraw software : the patient was 
 asked to expose his / her chest , upper limbs , and posterior superior iliac spines . the 
 scapular bony landmarks , that is , the superior angle , inferior angle , and lateral scapular 
 angle , were all palpated and marked . the lateral scapular angle was marked at a 5  cm 
 distance from the acromion . the spinous processes of c7 , the corresponding thoracic 
 vertebrae to the scapular bony landmarks , and the posterior superior iliac spines ( psiss ) 
 were marked . the c7 spinous process , inferior scapular angles , and the two psiss points were 
 the main bony landmarks corresponding to the scapular and spinal angles . digital photographs of the patient spine and both scapulae 
 were taken in the frontal plane in a sitting position with one digital video camera 
 ( dsc - w110 , sony corporation , tokyo japan ) . 5 . image analysis and angles calculation : the scapular and spinal angles were calculated 
 using computerized photogrammetry with the coreldraw graphics suite ( x5 ) software ( fig . 1fig . the qa angle represents the scapular 
 upward rotation angle on the affected side , while the qb angle represents that on the 
 non - affected side . the si is a line passing through the two inferior scapular angles , 
 while the pi is a line passing through the two psiss . the asi is a line drawn 
 perpendicular to the si line , while the api is a line drawn perpendicular to the pi 
 line . the angle of intersection of the two perpendicular lines , the asi and api , 
 represents the spinal lateral deviation angle ( s angle ) . ) . the scapular resting upward rotation angle is the angle between two lines , that is , 
 the line connecting the c7 spinous process and inferior angles and the vertical ( v ) line 
 passing through c7 . the qa angle represents the scapular upward rotation angle on the 
 affected side , while the qb angle represents that on the the non - affected side . the lateral 
 spinal deviation angle lies between two lines , that is , a line passing through the two 
 inferior scapular angles ( si ) and a line passing through the two psiss ( pi ) . after defining 
 the si and pi lines , a perpendicular line ( asi ) was drawn to the si , and another 
 perpendicular line ( api ) was drawn to the pi . the angle of intersection of the two 
 perpendicular lines , asi and api , represents the spinal angle ( s angle ) . the qa angle represents the scapular 
 upward rotation angle on the affected side , while the qb angle represents that on the 
 non - affected side . the si is a line passing through the two inferior scapular angles , 
 while the pi is a line passing through the two psiss . the asi is a line drawn 
 perpendicular to the si line , while the api is a line drawn perpendicular to the pi 
 line . the angle of intersection of the two perpendicular lines , the asi and api , 
 represents the spinal lateral deviation angle ( s angle ) . a selective six - week strengthening exercise program was applied for the shoulder girdle 
 muscles ( shoulder abductors and external rotators ) to the two groups . the patients received 
 3 sessions weekly ( a total of 18 therapeutic sessions ) . they received preparatory stretching 
 exercises for the pectoralis major , latissimus dorsi , rhomboids major and minor , and teres 
 major muscles prior to starting the strengthening exercises . in addition , trunk control 
 exercises , that is , active flexion , side bending , and rotation in a sitting position , were 
 applied . the study group received additional strengthening exercises focusing on the 
 scapular muscles , that is , the supraspinatus , serratus anterior , and upper trapezius 
 muscles . the data for shoulder muscle strength , scapular muscle strength , scapular and spinal 
 angles , and the score of motor assessment scale ( mas ) for stroke patients were collected 
 before and after treatment . numerical data were expressed as means and standard deviations or 
 medians and ranges as appropriate . the  test ( fisher s exact test ) was used to examine the relation 
 between qualitative variables . for quantitative data , comparison between two groups was done 
 using the independent mann - whitney test . seven patients did not complete the study due to 
 personal circumstances ( 4 patients ) , health problems ( 2 patients ) , or loss during follow - up 
 ( 1 patient ) . results are presented for 23 patients ( 10 in the control group and 13 in the 
 study group ) . demographic and clinical characteristics of the two groups are presented in 
 table 1table 1.general characteristics of patients in both the control and study groupscontrol groupn = 10study groupn = 13age ( yrs)52.25.253.63.2weight ( kg)79.95.980.75.7height ( cm)165.76.7166.64.9duration of illness ( months)8.82.38.12.0hemiparetic side ( rt / lt)3/72/11gender ( m / f)9/112/1 . the two groups were comparable in all characteristics . table 2table 2.shoulder abductor and external rotator peak torques in the two studied groups 
 before and after treatmentcontrol groupn = 10study groupn = 13shoulder abduction peak torque ( nm)before treatment23.49.923.98.7after treatment25.19.333.77.9% change , median ( range)10.3% ( 2.017.1%)32.5% ( 15.750.5%)*shoulder external rot . peak torque ( nm)before treatment9.74.89.44.8after treatment11.75.116.96.3% change , median ( range)18.3% ( 4.529.7%)48.7% ( 24.961.2%)*nm : newton meters . * significant difference between groups ; significant 
 difference within group shows the peak torque values of shoulder abductors and external rotators in 
 the two groups before and after the strengthening exercise program . before treatment , there 
 was no significant difference between the two groups in shoulder abduction and shoulder 
 external rotation peak torque . after treatment , both muscles showed significantly higher 
 peak torque in the study group compared with the control group . the two muscles showed 
 significant improvement in strength after the exercise programs in the two groups . * significant difference between groups ; significant 
 difference within group table 3table 3.supraspinatus , upper trapezius , and serratus anterior muscle peak forces in the 
 two studied groups before and after treatmentcontrol groupn = 10study groupn = 13supraspinatus peak force ( n)before treatment1.30.51.40.5after treatment1.50.42.20.5*% change , median ( range)10.8% ( 4.345.5%)33.3% ( 18.561.1%)*upper trapezius peak force ( n)before treatment2.30.42.30.5after treatment2.60.43.40.6*% change , median ( range)9.6% ( 3.621.7%)28.9% ( 12.564.3%)*serratus anterior peak force ( n)before treatment2.40.72.30.7after treatment2.50.63.10.6*% change , median ( range)7.0% ( 2.928.6%)25.7% ( 10.545.0%)*n : newtons . * significant difference between groups ; significant 
 difference within group shows the peak force values for the supraspinatus , upper trapezius , and 
 serratus anterior muscles in the two groups before and after the strengthening exercise 
 program . before treatment , there was no significant difference between the two groups in 
 supraspinatus , upper trapezius , and serratus anterior peak force . after treatment , the three 
 muscles showed significantly higher peak forces in the study group compared with the control 
 group . the three muscles showed significant improvement in strength after the exercise 
 programs in the two groups . significant difference between groups ; significant 
 difference within group table 4table 4.scapular upward rotation angle and spinal lateral deviation angle in the two 
 studied groups before and after treatmentcontrol groupn = 10study groupn = 13scapular upward rotation angle ( degrees)before treatment31.34.230.43.0after treatment33.33.836.62.4*% change , median ( range)6.1% ( 0.610.2%)15.9% ( 4.627.4%)*spinal lateral deviation angle ( degrees)before treatment7.32.27.72.1after treatment5.52.33.81.8% change , median ( range)27.3% ( 12.641.2%)51.8% ( 24.778.7%)**significant difference between groups ; significant difference within 
 group shows the scapular upward rotation angle and spinal lateral deviation angle in 
 the two groups before and after the strengthening exercise program . before treatment , there 
 was no significant difference between the two groups in the scapular upward rotation and 
 spinal lateral deviation angles . after treatment , the scapular upward rotation angle was 
 significantly larger in the study group compared with the control group . after treatment , 
 the spinal lateral deviation angle was significantly smaller in the study group compared 
 with the control group . the two angles showed significant changes after the exercise 
 programs in the two groups . however , the percentage of change was significantly higher in 
 the study group . * significant difference between groups ; significant difference within 
 group the peak force of the three scapular muscles showed a strong positive correlation with the 
 scapular upward rotation angle and strong negative correlation with the spinal lateral 
 deviation angle , especially after treatment ( table 
 5table 5.correlation between the peak forces of the three scapular muscles and the 
 scapular upward rotation angle and lateral spinal deviation anglescapular upward rotation anglespinal lateral deviation anglepretreatment peak forcesupraspinatus0.457*0.638*upper trapezius0.2240.361serratus anterior0.462*0.671*posttreatment peak forcesupraspinatus0.797*0.592*upper trapezius0.713*0.855*serratus anterior0.634*0.862*values are presented as correlation coefficients ( r ) . * significant correlation ) . the two angles showed significant negative correlation before treatment ( r = 
 0.422 , p = 0.045 ) and after treatment ( r = 0.619 , p = 0.002 ) . this study demonstrated beneficial effects of a six - week strengthening exercise program for 
 the shoulder girdle muscles and scapular muscles in hemiparetic patients on the strength of 
 these muscles and the spinal lateral deviation angle . strengthening of the scapular muscles 
 resulted in a significantly higher effect in these two aspects . there was a strong positive 
 correlation between the peak force of the three scapular muscles with the scapular upward 
 rotation angle and strong negative correlation with the spinal lateral deviation angle . scapular muscle strengthening was associated with a significant increase in the scapular 
 upward rotation angle and significant decrease in the spinal lateral deviation angle . the 
 two angles were positively affected by strengthening of the shoulder girdle muscles , but the 
 effect was more pronounced after scapular muscle strengthening . in fact , the peak torque 
 values of the shoulder abductors and external rotators were higher after scapular muscle 
 strengthening . this effect can be explained by the normal synergist coactivation reported 
 between shoulder girdle muscles working at the glenohumeral and scapulothoracic levels in 
 addition to the neurophysiologic effect of resisted exercises21 . improvement of the strength of the scapular muscles in the control 
 group despite the lack of training can also be explained by the synergist coactivation 
 between different shoulder muscles . the resting scapular upward rotation angle was specifically measured in the present study , 
 as it reflects the strength of the three studied scapular muscles , the trapezius , serratus 
 anterior , and supraspinatus . these muscles work together to maintain the scapula s elevation 
 and upward rotation orientation . we also measured the scapular and spinal angles in the 
 sitting position to eliminate the effect of unequal weight shifting on the lower limbs so 
 that we could concentrate on the effect of the shoulder girdle muscles22 . based on previous studies19 , 23,24,25 , we planned the training dose to be 1  h / d , 3 d / wk for 6 
 weeks ( 18 h ) . previous authors recommended 46 weeks as an optimum duration of strengthening 
 exercises to be effective in stroke patients . we extended to the maximum of six weeks , as 
 the extent of strength gain was positively correlated with the intensity and the number of 
 exercising units24 . based on the study of mottram26 , the 
 current study considered manual resisted exercises rather than any other types of 
 strengthening interventions . these exercises primarily reeducate the stability and control 
 around the scapula to improve postural alignment . folland and williams27 and falvo et al.28 found that resisted exercises may enhance the recruitment , firing 
 rate , and synchrony at the level of the motor neuron by enhancing neural adaptation . the shoulder muscles selected to be strengthened in the current study were abductors and 
 external rotators , as shoulder external rotation is more important than internal rotation in 
 providing stability to the shoulder joint26 . this can be explained 
 by synergist coactivation of these muscles during scapular muscle strengthening . escamellia 
 et al.29 reported that shoulder abductors 
 and external rotators showed increased firing activity during serratus anterior muscle 
 strengthening with a forward pushing exercise . the significant improvement in the resting scapular upward rotation angle in the two groups 
 in this study can be attributed to the relation between scapulothoracic stability and 
 trapezius - serratus anterior force coupling30 . shoulder stability exercise can improve range of motion , muscle 
 strength , and grasping power of the upper limb31 . improvement of scapular muscle strength can also influence 
 postural stability of the shoulder girdle and the proximal trunk32 . in a group of normal young males , alizadeh et al.33 tested the effect of a progressive exercise program including 
 resistive strengthening , stretching , and postural exercises on the position of the scapula . this 
 improvement was correlated with improved strength of the scapular elevators , mainly the 
 trapezius muscle . the primary result of the present study was the significant improvement of 
 the spinal alignment in the two groups with better improvement after scapular muscle 
 strengthening . the spinal lateral deviation angle showed strong negative correlation with 
 the peak force of the three scapular muscles . to our knowledge , this study seems to be the 
 first to consider the influence of shoulder muscle strengthening on spinal alignment in 
 patients with stroke . gomes et al.34 
 published a case study that supports the effect of shoulder girdle posture on spinal 
 alignment in patients with stroke . they reported mild improvement of scapular position and 
 spinal lateral deviation after global postural reeducation ( gpr ) exercises for scapular and 
 pelvis girdle muscles , and they attributed the improvement in spinal alignment to the effect 
 of the gpr technique in providing better scapular and pelvic alignment . mottram26 and williams et al.35 found that scapulothoracic joint stability provided mainly 
 by trapezius - serratus anterior coupling had an important contribution to the core stability 
 of the trunk . in addition , the rotator cuff group could have an influence on scapular 
 alignment and therefore core stability , although it does not have direct attachments to the 
 spinal column or rib cage29 . in 
 conclusion , this can be considered a pilot study on the effect of shoulder and scapular 
 muscle strength on postural alignment in stroke patients . the study provided preliminary 
 evidence that manual resisted exercises for shoulder muscles ( external rotators and 
 abductors ) and scapular muscles ( serratus anterior , trapezius , and supraspinatus ) 
 significantly reduced lateral spinal deviation angle in the sitting position . in addition , 
 these exercises rectified the position of the scapula on the affected side . the limitations of this study can be summarized as the relatively small sample size , which 
 limits generalization of the study s results . in addition , inclusion of only patients above 
 45  years old did not allow evaluation of the physiotherapy program for younger patients who 
 are involved in higher grades of activity and need gait correction .
[ purpose ] this study investigated the effect of shoulder girdle strengthening , 
 particularly the scapular muscles , on poststroke trunk alignment . [ subjects and methods ] 
 the study involved 30 patients with residual hemiparesis following cerebrovascular stroke . 
 patient assessment included measuring shoulder muscle peak torque , scapular muscles peak 
 force , spinal lateral deviation angle , and motor functional performance . 
 patients were 
 randomly allocated either to the control group or the study group and received an 
 18-session strengthening program including active resisted exercises for shoulder 
 abductors and external rotators in addition to trunk control exercises . 
 the study group 
 received additional strengthening exercises for the scapular muscles . 
 [ results ] the two 
 groups showed significant improvement in strength of all shoulder and scapular muscles , 
 with higher improvement in the study group . 
 similarly , the lateral spinal deviation angles 
 significantly improved in both groups , with significantly higher improvement in the study 
 group . transfer activity , sitting balance , upper limb functions , and hand movements 
 significantly improved in the two groups , with higher improvement in the latter two 
 functions in the study group . 
 [ conclusion ] strengthening of shoulder girdle muscles , 
 particularly scapular muscles , can significantly contribute to improving the postural 
 alignment of the trunk in patients with poststroke hemiparesis .