Stroke is the main
cause of long-term disability in adults.1 Regaining trunk control
has been identified as an important early predictor of functional recovery
after stroke. Proximal trunk control is a prerequisite for distal limb movement
control, balance stability and functional ability.2
Decreased
trunk control leads to poor bilateral integration, impaired automatic postural
control, and hence increased risk of falls.3 Balance problems have
been implicated in the poor recovery of activities of daily living, mobility4
and an increased risk of falls.5
Also, Prediction of
functional abilities at an early stage enables clinicians to select appropriate
treatment programs and goals, facilitate a proper discharge plan, and
anticipate the need for home adjustments and community support.6
Aim of Work: To examine the trunk muscle control in a group
of chronic stroke patients and to find out if there is a direct correlation
between poor trunk muscle control on one hand and balance and functional
abilities on the other hand. We looked into whether or not one of our outcome
measures may be used as a clinical predictor of functional recovery after
stroke.
PATIENTS AND METHODS
Forty
adult ambulant ischemic chronic stroke patients (more than 6 months after
stroke onset) were recruited from the outpatient clinic and Balance System
laboratory of Faculty of Physical Therapy, Cairo University
between October 2011 and January 2013.
All
patients recruited were experiencing their first ever stroke, had at least
average cognitive functions that enabled them to follow commands. Patients were
excluded if they had severe proprioceptive deficit, any other neurologic or
orthopedic disorders, disabling visual or hearing impairment or unstable
medical condition.
All
patients were examined using the trunk impairment scale (TIS)7 to
assess trunk control (primary outcome measure). This scale has a total score of
23 and it includes 7 points for static, 10 points for dynamic sitting balance,
and 6 points for coordination. TIS scores of 21 or more indicate normal trunk
muscle function.8 Balance was also assessed using the dynamic limits
of stability test and the overall stability index (OASI) that was done using
the automated Biodex Balance System. Subsequent functional limitation was
examined using the motor subscale of the Functional Independence Measure
(FIM_motor).
Statistical Analysis
The collected data
were statistically analyzed using SPSS statistical software (version 18).
Descriptive statistics (mean and standard deviation) were used to assess the
demographic data of all patients. Pearson correlation coefficient (r) was used
to study the correlation between TIS (total score and scores of its subscale)
and both (balance and functional abilities measures); Univariate regression
analysis (R2) was used to determine to what extent trunk control
affects balance and functional abilities in stroke patients, and to compare
between the subscales of TIS in relation to balance and functional abilities.
P<0.05 is considered of statistical significance and P ≤0.0001is considered highly significant.
RESULTS
Forty patients with
first-ever ischemic stroke were recruited. The sample included 29 males (72.5%)
and 11 females (27.5%) with a mean age of 56.1±5.45 (Range: 50-65) and mean
duration after stroke of 9.8±2.68 (Range: 6-15 months). Twenty-four patients (60%) had left side
affection while 16 (40%) had right side affection. Results of the patients'
assessment are described in Table (1).
The TIS total score
was low with a median of 16 (IQR 13-20). Only one patient (2.5%) had a score of
21, which represents normal trunk control. Upon correlating the TIS to other
measures of balance and function, there was a highly significant direct
correlation between the TIS total score and each of the OASI, dynamic limits of
stability and the FIM (r=0.929 / P=0.0001 and r=0.985 / P=0.0001,
respectively). In addition, there was negative highly significant correlation
between the TIS total score and OASI (r =-0.945, P=0.0001). The TIS subscales,
namely the static and dynamic sitting balance items also significantly
correlated with the OASI, dynamic limits of stability and the FIM_motor scale
(Table 2).
Results of univariate
regression analysis between the TIS total score and its subscores on one side
and measures of balance and functional skills (OASI, dynamic limits of
stability, and FIM_motor) on the other side are presented in Table (3). All
results for the dynamic sitting balance and total score are significant. This
indicates that there is a high probability of having low scores of OASI,
dynamic limits of stability and FIM_motor when the TIS total score or dynamic
sitting balance are low. Nevertheless, the coordination scale results were all
insignificant. For the static sitting balance component of the test, the
results were significant except the values between the sitting balance score
and the dynamic limits of stability test.
Table 1. Sample characteristics.
|
Median (IQR)
|
Range
|
TIS_total
|
16 (13-20)
|
11-21
|
TIS_static sitting balance
|
7(6-7)
|
5-7
|
TIS_dynamic sitting balance
|
7(5-9)
|
4-10
|
TIS_coordination
|
2 (2-4)
|
1-4
|
OASI
|
3.8 (2.95-5.1)
|
2.1-7.3
|
Dynamic limits of stability
|
13 (10-23)
|
8-36
|
FIM_motor
|
62.5 (57-70)
|
49-77
|
FIM_motor: Functional
Independence Measure-motor subscale, OASI overall stability
index, TIS trunk impairment
scale
Table 2.
Correlation between TIS total score and subscores and each of OASI, overall
dynamic limits of stability and FIM.
|
OASI
|
Dynamic limits of stability
|
FIM_motor
|
TIS_total
|
r= -0.95
p=0.0001*
|
r =0.93
p =0.0001*
|
r =0.99
p =0.0001*
|
TIS_static sitting
balance
|
r= -0.79
p= 0.0001*
|
r =0.63
p =0.0001*
|
r =0.78
p =0.0001*
|
TIS_dynamic sitting
balance
|
r= -0.93
p= 0.0001*
|
r =0.92
p =0.0001*
|
r =0.96
p =0.0001*
|
TIS_coordination
|
r= -0.81
p= 0.0001*
|
r =0.87
p =0.0001*
|
r =0.88
p =0.0001*
|
FIM_motor Functional
Independence Measure-motor subscale, OASI overall stability
index, r correlation coefficient, TIS trunk impairment scale
*significant at P<0.01
Figure 1. Correlation between TIS total score and
FIM_motor score.
Table 3. Univariate regression analysis between TIS
total score and subscores and each of OASI, overall dynamic limits of stability
and FIM. Values presented as R2 (p value).
|
OASI
|
Dynamic limits of stability
|
FIM_motor
|
TIS_total
|
0.89 (p <0.0001*)
|
0.86 (p <0.0001*)
|
0.97 (p <0.0001*)
|
TIS_static sitting
balance
|
0.9 (p =0.001*)
|
0.89 (p >0.05)
NS
|
0.97 (p <0.0001*)
|
TIS_dynamic sitting
balance
|
0.9 (p <0.0001*)
|
0.89 (p <0.0001*)
|
0.97 (p <0.0001*)
|
FIM_motor Functional
Independence Measure-motor subscale, NS not significant, OASI overall stability index, r correlation coefficient, TIS trunk impairment scale
*significant at P<0.01
Figure 2. Regression model of the TIS total score and
FIM_motor score showing
a strong
positive interaction between both variables (R2 =0.97, p <0.0001).
DISCUSSION
We
aimed to assess the state of trunk muscle control in stroke patients at least
six months after the onset. Several studies had shown that chronic stroke
patients had poor trunk control.9-11 We investigated the trunk
muscle control in chronic stroke patients with good recovery, so we only
recruited patients who can walk independently. We used the TIS as it is more
sensitive in detecting changes in trunk muscle control.9
Our findings showed
that 39/40 patients had a degree of trunk muscle control impairment relative to
age matched controls reported in the literature.8 The median score
was 16 which is equivalent to 69.6% of the total score. Trunk impairment can be
explained by post-stroke affection of trunk muscle strength, neural control and
trunk proprioception which are prerequisites for good trunk control and
provision of stable foundation for movement.12
Our second aim was to
find out whether there is a correlation between trunk muscle control problems
and balance and/or functional activities of our selected patient group. Our
results demonstrated a highly significant correlation between the TIS total
score, TIS subscores on one side and balance and functional activities on the
other side. This is concordant with other studies that showed that trunk flexion
and extension muscle weakness when assessed clinically13 or by CT14
directly correlated with balance, functional recovery scores13,14
and speed of gait.14
The positive highly
significant effect of trunk control on balance and functional abilities of stroke
patients can be attributed to the fact that, the trunk is the central key point
of the body that provides proximal stabilization. Lack of this stabilization
after stroke influences the affected limbs profoundly-any attempt to move
upright against gravity leads to an increase of distal spasticity-which in turn
affect the patient’s balance control, mobility and functional capacity.
In addition, control
of movement proceeds from proximal to distal body regions; so, if an improved
level of proximal trunk control were attained, a better distal limb control
might be anticipated during balance and functional performance.15
The final target of
our study was to look into the best clinical predictors of trunk muscle control
and subsequent functional recovery. Regression analysis results showed that the
TIS total score and dynamic sitting balance subscore show the best signal in
terms of predicting balance and functional outcomes (table 3). We would suggest
the use of the dynamic sitting balance portion of the TIS as a valid assessment
tool of trunk muscle control that will also serve to predict future functional
recovery.
Conclusion
This study highlights
the role of trunk muscle control as an independent predictor of functional
recovery. This can be rapidly and reliably assessed using the TIS dynamic
sitting balance subscale. These findings should propel our neurorehabilitation
teams to objectively test and subsequently work on regaining efficient trunk
control even in stroke patients who recovered the ability to walk again.
[Disclosure: Authors report no conflict of interest]
REFERENCES
1.
Monaco M, Trucco M, Monaco R,
Tappero R, Cavanna A. The relationship between initial trunk control or
postural balance and inpatient rehabilitation outcome after stroke: a prospective
comparative study. Clin Rehab. 2010; 24(6): 543-54.
2.
Karthikbabu S, Chakrapani M, Ganeshan S,
Rakshith K, Nafeez S, Prem V. A review
on assessment and treatment of trunk in stroke: a need or luxury. Neural Regen
Res. 2012; 7(25): 1974-77.
3.
Cabanas-Valdés R, Cuchi G, Bagur-Calafat C. Trunk training exercises approaches for
improving trunk performance and functional sitting balance in patients with
stroke: a systematic review. NeuroRehabilitation. 2013; 33(4): 575-92
4.
Lamb S,
Ferrucci L, Volapto S. Risk factors for falling in home-dwelling older women
with stroke. Stroke. 2003; 34(2): 494-01.
5.
Visser
J, Carpenter M, van der K, Bloem B. The clinical utility of posturography. Clin
Neurophysiol. 2008; 119(11):2424-36.
6.
Wang C, Hsueh I, Sheu C, Hsieh C. Discriminative, Predictive, and
Evaluative Properties of a Trunk Control Measure in Patients with Stroke. Phys
Ther. 2005; 85(9):887-94.
7.
Verheyden G, Mertin J, Preger R, Kiekens C.
The Trunk Impairment Scale: a new tool to measure motor impairment of the trunk
after stroke. Clin Rehab. 2004; 18:326-34.
8.
Verheyden G, Nieuwboer A, Feys H, Thijs V, Vaes K, De Weerdt W. Discriminant ability of the
Trunk Impairment Scale: A comparison between stroke patients and healthy
individuals. Disabil Rehabil. 2005; 27(17):1023-8.
10. Messier S, Bourbonnais D, Desrosiers J, Roy Y. Dynamic
analysis of trunk flexion after stroke. Arch Phys Med Rehabil. 2004; 85:
1619-24.
11. Winzeler-Mercay U, Mudie H. The nature of the effects of
stroke on trunk flexor and extensor muscles during work and at rest. Disabil
Rehabil. 2002; 24:875-86.
12. Ryerson S,
Byl N, Brown D, Wong R. Altered Trunk Position Sense and Balance Functions
after Stroke. J Neurol Phys Ther. 2008; 32(1):14-20.
13. Karatas M, Cetin N, Bayramoglu M, Dilek A. Trunk muscle
strength in relation to balance and functional disability in unihemispheric stroke patients.
Am J Phys Med Rehabil. 2004; 83:81-7.
14. Tsuji T, Liu M, Hase K, Masakado Y, Chino N. Trunk muscles
in persons with hemiparetic stroke evaluated with computed tomography. J
Rehabil Med. 2003; 35:184-8.
15. Karthikbabu S, Chakrapani M, Ganeshan S, Rakshith K,
Nafeez S, Prem V. A review on assessment
and treatment of trunk in stroke: a need or luxury. Neural Regen Res. 2012;
7(25):1974-7.
الملخص العربى
تأثير التحكم في الجزع على الاتزان والقدرات الوظيفية عند مرضى السكتة الدماغية المزمنين
التحكم في الجذع شرط رئيسي للاتزان والاستعمال المنسق للأطراف في النشاطات الوظيفية اليومية. يهدف هذا البحثِ إلى تقييم التحكم في الجذع عند مرضى السكتة الدماغية ودراسة مدى تأثير اختلال التحكم في الجذع على الاتزان والقدرات الوظيفية لهؤلاء المرضى. كما يهدف إلى تحديد أي من المقاييس الثانوية لمقياس اختلال الجذع الرئيسي هو المؤشر الحقيقي للاتزان والقدرات الوظيفية لهؤلاء المرضى وإيضاح مدى تأثير اختلال الاتزان على الأداء الوظيفي لهم.
أجريت هذه الدراسة على أربعين مريضا مزمنا بالسكتة الدماغية المترددين على العيادة الخارجية بكلية العلاج الطبيعي- جامعة القاهرة. تضمنت التجربة تقييم التحكم في الجذع عن طريق مقياس اختلال الجذع وقياس الاتزان الحركي بجهاز الاتزان البيودكس، وتقييم القدرات الوظيفية لهؤلاء المرضى باستخدام المقياس الوظيفي اللااعتمادي.
نتائج