INTRODUCTION

Stroke is the most common neurological disorder that represents a major cause of disability. It is a significant health problem that needs an extensive and continuous rehabilitation. Clinically, a number of defects are possible after stroke, including impairments of motor, sensory and perceptual functions¹.

The clinical manifestations and effects of a cerebrovascular stroke depend on many factors including which part of the brain is damaged and how severely it is damaged. Malalignment of trunk in stroke patients occurs due to several reasons; inactive shoulder elevator muscles on the affected side that leads to shoulder depression accompanied by increasing muscle activity of the scapular depressor muscles. Postural malalignment may be secondary to unilateral weakness (specially around the pelvis), unbalanced skeletal muscle activity and perceptual dysfunction².

Stroke patients commonly lose their ability to perform postural adjustment and maintain postural alignment because of spasticity, weakness, loss of equilibrium and righting reactions, therefore the trunk often assumes an asymetrical posture. Loss of trunk control is commonly observed in patients who have had stroke, it may lead to dysfunction in upper and lower limb control³.

The Formetric instrument system serves for determination of the geometry of the back surface of the human beings. It represents a reliable method for three dimensional back shape analysis and reconstruction of spinal deformities. Its mechanism depends upon the use of a system of horizontal parallel white light lines projected onto the back surface of the patient^4,5.

The aim of this study was to assess trunk and pelvis malalignment in stroke patients in relation to the duration of illness and degrees of spasticity.

PATIENTS AND METHODS

Patients:

Sixty stroke patients diagnosed on clinical and neurological basis, CT and MRI studies. Their age ranged from 45 to 65 years. Fourteen were females, 46 were males. They were divided into three equal groups according to duration of illness: Group A: with duration of illness from 6 to 12 months. Group B: with duration of illness more than 12 and up to 18 months. Group C: with duration of illness more than 18 and up to 24 months. Each group was subdivided into two subgroups (A₁ + A₂, B₁ + B₂ and C₁ + C₂) according to the degree of spasticity, (A₁, B₁, C₁ showed mild spasticity) and (A₂, B₂, C₂ showed moderate spasticity). Assessment of spasticity was performed through the application of the modified Aschworth Scale Technique⁶.

Inclusion Criteria:

Clinical presentation of patients with a single unilateral stroke that received their neurological treatment and their physical therapy program during the hospital stay. The duration of their illness was not less than six months. They were able to walk without assistive device and they follow all instructions.

Exclusion Criteria:

The patients were free from leg length discrepancy, advanced orthopedic problems or old lower limb fractures. They have no previous musculoskeletal abnormalities.

Neurological Examination:

Full history taking including duration and progression of symptoms, clinical and neurological examination which involved; cranial nerves, fundus examination, assessment of degrees of reflex affection, type and distribution of sensory affection. Radiological CT and MR imaging for each patient were assessed.

Instrumentation:

The optical 3D measurement system Formetric II device⁷ was used for the spine analysis and posture measurement of the trunk. It provides a fast, contactless, and radiation-free static measurement of the back.

Neurological assessment of muscle tone; was done according to the modified Aschworth scale for grading spasticity⁶. Assessment of trunk control test and trunk range of motion were performed through the use of the modified Schober flexion technique⁷.

Statistical Analysis:

Data were coded and entered using the Statistical Package for Social Science (SPSS), version 15. Data were arranged using mean, standard deviation and range for quantitative variables, and using number and percentage for qualitative variables. Comparison between groups was done using Chi-square test for qualitative variables. The ANOVA test was used for comparison of means for more than two groups, and spearman correlation coefficient was used to determine positive or negative correlation between variables. P-values less than or equal to 0.05 were considered as statistically significant.

RESULTS

I.       Demographic data concerning the mean value of age for patients in group A was 56.75±6.41 years, in group B was 54.6±4.66 years, in group C was 53.2±5.34 years. The mean value of height for patients in group A was 166.65±5.08 cm, in group B was 165.7±4.72 cm, and in group C was 167.9±6.6 cm. The mean value of weight for patients in group A was 74.2±7.68 Kg, for patients of group B was 74.15±10.53 Kg, and for patients in group C was 78.95±11.45 Kg. The mean value of body mass index (BMI) for patients in group A was 25.55±3.04 Kg/m², in group B was 27.02±3.59 Kg/m², and in group C was 28.02±4.55 Kg/m². These results revealed no statistical significant difference among the examined groups of patients (Table 1).

Spasticity among the examined groups of patients: After application of the modified Aschworth Scale Technique, patients who had scores of 1 or 2 were considered to have mild spasticity and those with scores 3 or 4 were considered to have moderate spasticity. In group A; ten patients showed mild spasticity (group A₁) and the other ten patients showed moderate spasticity (group A₂). In group B, there were six patients with mild spasticity (group B_­1) and 14 patients with moderate spasticity (group B₂). In group C nine patients showed mild spasticity (group C₁) and 11 patients showed moderate spasticity (group C₂).

II.     Trunk Range of Motion (ROM): The trunk flexion for patients in group A had mean value of 23.25±4.85 cm, for patients in group B; 21.05±4.32 cm, and for patients in group C; 21.1±5.17 cm. These results showed no statistical significant difference for trunk flexion among the groups of patients (P=0.2). The trunk extension for patients in group A; had mean value of 4.8±1.05 cm, in group B, 4.4±1.78 cm and in group C; 4.75±1.48 cm. These results showed no statistical significant difference for trunk extension among the groups of patients (P=0.64). The right lateral trunk side bending for patients in group A; had mean value of 26.1±4.88 cm, in group B; 24.65±4.65 cm, and in group C; 20.85±3.09 cm. These results showed highly statistical significant difference for right lateral trunk side bending among the groups of patients (P=0.001). The left lateral trunk side bending for patients in group A; had mean value of 28±6.28 cm, in group B; 26.1±6.23 cm, and in group C; 21.1±2.88 cm. These results showed highly statistical significant difference for left lateral trunk side bending among the groups of patients (P=0.001) (Table 2).

III.   Trunk Malalignment: The mean values of lateral trunk deviation were 8.8±2.28 mm in group A, 14.3±2.2 mm in group B and 19.15±7.59 mm in group C. There was a statistical significant difference among the examined groups (P<0.01). The mean values of pelvic tilting were 2.9±2.46 mm in group A, 4.9±3.09 mm in group B and 18.15±4.14 mm in group C. There was a statistical significant difference among the examined groups (P<0.01). The mean values of the trunk control test were 71.75±19.8 in group A, 62.2±19.32 in group B and 55.5±22.31 in group C. There was a statistical significant difference among the examined groups (P<0.01) (Table 3).

IV.    Correlation between Duration of Illness and Malalignment of Trunk and Pelvis: There was a significant correlation between duration of illness and lateral trunk deviation; in both groups A and B; in group A (r = +0.53, P<0.01), in group B (r = +0.54, P<0.01). In group C; there was a high significant correlation between duration of illness and lateral trunk deviation (r=+0.71, P<0.001). There was a high significant correlation between duration of illness and lateral pelvic tilting, it was (r = +0.72, P<0.001) in group A; (r = +0.77, P<0.001) in group B; and it was (r = +0.77, P<0.001) in group C. There was a negative significant correlation between the duration of illness and the trunk control test in group A (r = -0.5, P<0.02) and group B (r = -0.55, P<0.04), while in group C; it was (r = -0.64, P<0.03) (Table 4).

Correlation between Malalignment of Trunk as well as Pelvis and the Degree of Spasticity among the examined patients: There was a moderate significant correlation between the degree of spasticity and lateral trunk deviation (r=+0.56, P<0.01) in groups A₁, A₂. There was a strong significant correlation between the degree of spasticity and the lateral trunk deviation in groups B₁, B₂ (r = +0.75, P<0.001) as well as in groups C₁, C₂ (r = +80, P>0.001). There was a moderate significant correlation between the degree of spasticity and the lateral pelvic tilting in groups A₁, A₂ (r = +0.5, P<0.02). There was a high significant correlation between the degree of spasticity and the lateral pelvic tilting in groups B₁, B₂ (r=+0.55, P<0.01) as well as in groups C₁, C₂ (r=+0.64, P<0.002). There was a high significant correlation between the degree of spasticity and the trunk control test among the examined six groups of patients. It was (r = -0.69, P<0.001) in groups A₁, A₂ and it was (r = -77, P<0.001) in groups B₁, B₂ and it was (r=-91, P>0.001) in groups C₁, C₂  (Table 5).

Table 1. The mean, standard deviation and the P-values for patients' demographic data for each group of stroke patients.

Cm centrimeter, BMI Kg/m²  Body Mass Index Kilogram per meter square, Kg Kilogram, SD Standard deviation, yrs years

Table 2. Demonstrates comparison between the results of the trunk range of motion among the examined groups of stroke patients.

SD Standard deviation                                                            

**significant  at p<0.01.

Table 3. Comparison between the results of trunk and pelvis malalignment among the examined groups of stroke patients.

SD Standard deviation                                                            

**significant  at p<0.01.

Table 4. Correlation between the duration of illness and trunk and pelvis malalignment among the examined groups of stroke patients.

r Spearman correlation coefficient                                                          

**significant  at p<0.01.

Table 5. Correlation between the degree of spasticity, and lateral trunk deviation, trunk control test as well as pelvic malalignment in the examined groups of stroke patients.

r Spearman correlation coefficient                                                          

*significant  at p<0.05     **significant  at p<0.01

DISCUSSION

The purpose of this study was to assess trunk and pelvis malalignment in stroke patients with different degrees of spasticity and to correlate their malalignment with the duration of illness. The results showed that there was a statistically significant correlation between right and left trunk side bending and the duration of illness as well as to the degree of spasticity. It was clearly demonstrated that in hemiplegic patients, there was prominent weakness in the abdominal muscles accompanied by constant lateral trunk deviation. These observed changes were explained through the fact that, patients with stroke commonly lose their ability to maintain postural alignment because of spasticity, weakness, loss of equilibrium and righting reactions, so the trunk often assumes an asymmetrical posture and the patients usually have a long C-shaped, collapsing curve⁸. It was also demonstrated that hemiplegic patients have been shown to bear a greater percentage of body weight on the unaffected limb than on the affected side, so trunk asymmetry appears⁹.

It was assumed that scoliosis usually appear in stroke patients as a result of an increase in the skeletal muscle activity on one side of the trunk or due to weakness of muscles in the other side, soft tissue shortening, fixed deformity and inability to perceive midline. Postural malalignment in stroke patients are usually due to immobilization, spasticity, flaccidity, lack of variation in limb postures or combination of these various factors⁽²⁾. It may be also due to the presence of low synchronization between the activity of the unaffected extensors and the malfunctions of the paretic side, compared to the non-paretic one¹⁰.

Hemiplegic patients usually swayed over a larger area, and consistently displace laterally over the non-affected lower extremity, this lateral sway displacement correspond to asymmetric loading patterns with the non-affected leg¹¹. Lateral trunk deviation and lateral swaying was previously explained by the fact that the progress in the degree of spasticity in stroke patients causes an increase in the activity of the spastic muscles that may result in characteristic posture of the body, resulting in formation of fixed deformities¹².

                In conclusion, this study confirms the possible association between impairment of trunk control functions and malalignment of trunk and pelvis which are commonly observed in patients who have had strokes. These patients lose their ability to perform postural alignment, therefore the trunk often assumes an asymmetrical posture. A significant positive correlation was found between duration of illness, degrees of spasticity and trunk and pelvis malalignment. Evaluation of trunk and pelvis alignment should be done thoroughly as an essential part for the assessment and follow-up treatment of patients with cerebral vascular strokes.

[Disclosure: Authors report no conflict of interest]

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