Development anD use of a new tool for assessing upper anD lower limb synergies in people with stroke

background. While abnormal motor synergy is a major characteristic of stroke survivors, a major concern for reha- bilitation clinicians, especially physiotherapists, deals with its assessment, evaluation, and meaningful intervention. Objectives. This study was about the development and use of a new tool to measure accuracy in performance of functional motor synergies and activities of daily living in people with stroke. Materials and methods. Thirteen stroke survivors comprising eight with left hemiplegia and five with right hemiplegia participated in this study. Each subject was instructed to perform a total of twenty six activities which involved touching designated point and stepping on designated quadrants. They were all assessed using a developed synergy assessment chart, on which was recorded the synergy assessment score and a developed synergy assessment board, on which was recorded the activity performance profile and abnormal synergy. results. This study showed that stroke survivors typically exhibit limitation of their motor, functional and daily living activities. Activity performance profile showed that 44.23% of participants exhibited abnormal synergy, 43.98% of activities could be performed in less than 1.5 seconds and 51.53% of activities could be performed in more than 1.5 seconds. Reliability test gave a value of 0.87 using the Cronbach’s alpha. The new tool showed a good inter-item relationship when correlated with the Berg balance scale and Barthel Index (p < 0.001). conclusion. From the data gathered, the synergy assessment chart and board has a good reliability and inter-item correlation when compared with Berg balance scale and Barthel Index.


INtrODUctION
stroke is a common neurological disorder and a major cause of long-term disability, involving both motor and functional tasks (1). the disease is expected to increase in low and middle-income countries like nigeria (1). it has been asserted that common upper extremity impairment after stroke includes: paresis, loss of fractionated movement, abnormal muscle tone and/or changes in somatosensation (2). gerdienke et al. (3) further explained that this reduction in ability to coordinate movement, among others, can be expressed as an involuntary coupling of movements (3). these researchers also distinguished two patterns of coupling to describe the motor behavior of stroke survivors: a flexion pattern and an extension pattern (3). For the upper extremity, the flexion pattern includes shoulder abduction, shoulder external rotation, elbow flexion and forearm supination, while the extension pattern comprises shoulder adduction, shoulder internal rotation, elbow extension and forearm pronation. this coupling of muscles, also referred to as synergy, to perform a motor or functional task is of utmost interest in the rehabilitation of people disabled by stroke (3). assessment and evaluation of synergies following stroke have shown that some muscle groups outside the known synergy are difficult to rehabilitate (4). Beer et al. (5) asserted that in isometric contractions of chronic stroke survivors, the generation of shoulder abduction torques is coupled to simultaneous generation of elbow flexion torques: the higher the shoulder abduction torque, the more elbow flexion is generated (6). When extending this research to dynamic situations, they found limitations in elbow extension during reaching without arm support when the arm has to be lifted actively at shoulder height, since active shoulder abduction provoked simultaneous elbow flexion torques (5). Various outcome measures can be used in the assessment of muscle synergy. these outcome measures include: electromyography and neuro-rehabilitation robot (7). these outcome measures are cumbersome to administer, expensive and usually not within easy reach of a physiotherapist. Urra et al. (8) asserted that current assessment scale do not take patient's neuromuscular state and synergy into consideration. since the motor synergy is so vital to motor and functional performance, the need for a useful tool to assess it has become imperative. this study therefore is aimed at developing a new tool for assessing upper limb and lower limb synergy among stroke survivors.

MAtErIALs AND MEtHODs
the study involved 13 stroke survivors (both male and female) with at least 3 months duration of stroke (DOs) who were receiving treatment at the Physiotherapy Department of the lagos University teaching Hospital (lUtH), idi-araba, lagos. this study was designed to develop and use a new tool to assess upper limb and lower limb muscle synergies among stroke survivors. stroke survivors with the following criteria were included into the study: intact cognition, intact vision, literate, Berg Balance scale score greater or equal to forty one, Barthel index score greater than or equal to 50, and tolerable shoulder pain. the participants were selected using sample of convenience. Prior to the study ethical clearance was obtained from the research and ethics committee of lUtH.
Each participant was asked to perform specific movement pattern using the synergy assessment board for upper limb, SAB-U) (Fig. 1) and synergy assessment board for lower limb, SAB-L (Fig. 2), values were recorded on the synergy assessment chart for upper limb, sac-U and lower limb, sac-l respectively. the participant was asked to perform each movement pattern twice (i.e. touching each quadrants and placing the foot one each quadrant). the time t 1 and t 2 (in seconds) was taken and the mean time (t M ) was calculated. as the participant performed each action, the movement was observed and crossed checked for the expected movement used on the synergy assessment chart. abnormal synergies were noted and documented. Other information collected included the age of the participant, duration of stroke (DOs) and side of affectation. Duration of stroke (in months) was given as the period from the onset of the stroke to when the tool was administered.
the recordings of events on the boards had 3 domains. The first domain assessed achievability, the second domain assessed mean time to perform activity and the third domain assessed abnormal synergy. the sum of score for achievability was used as the synergy assessment score (sas). achievability was determined from the mean time. When a participant was able to perform the activity in less than 1.5 seconds, a score of 2 was given. When a participant performed the activity in more than 1.5 seconds, a score of 1 was given. When a participant could not perform the activity, a score of 0 was given. Abnormal synergy was also assessed. this was scored based on observation and cross referencing with the normal synergy on the synergy assessment chart.
results obtained were sorted out into 3 categories. these categories consisted of: • group 1 -these results included all participants regardless of what hemisphere was affected • group 2 -these results included of all participants that had left hemiplegia. • group 3 -these results included all participants that had right hemiplegia. The lower limb was assessed first with the use of SAB-L. The participant was asked to stand on quadrant 0. Once the participant stood comfortably, with both legs within the quadrant 0, instructions were given to the participant to place limb of appropriate quadrant. the time taken to complete each action (i.e. place each limb form quadrant 0 to required quadrant) was record.
The upper limb was assessed using the SAB-U. the length of the participant upper limb was taken, from the acromion to the middle finger. The length in meters was taken and two-third of this length was used as the distance of participant to SAB-U. this was done due to variation in the upper limb length of each participant. the participant was asked to stand at the calculated distance away from SAB-U. The lower border of SAB-U was placed such that it lies at the same level with the sternal notch. this was done due to the variation in the height of individual participant. the midpoint of each quadrant was designated. the participant was instructed to touch the midpoint of each quadrant beginning with 1a and ending at 3c. all participants were asked to perform each action twice for both upper limb and lower limb. the time t 1 and t 2 was taken and the mean time t M was calculated. t M was calculated. as the participant performs each action, the movement was observed and crossed checked the expected movement used the synergy assessment chart. abnormal synergy was noted and documented.
the highest score possible for each upper limb is 18 (a total of 36 for the upper limb) while the highest score possible for each lower limb is 8 (a total of 16 for the lower limb). the highest total score possible is 52. Obtained values were recorded on a synergy assessment chart (sac).
this tool can be administered in a time range of 10-15 minutes.
the data were analysed using the statistical Package for social sciences (sPss), version 21. Descriptive and frequency statistics were obtained for the variables. the cronbach's alpha was calculated to determine the inter-item correlation between BBS, BIADL and SAS. A P value of < 0.01 was considered statistically significant.

GrOUP 1
Results obtained showed a mean age of 50 ±13.45, BIADL 86.62±9.46, BBS 45.38±0.51, MMse 28.69±5.39, sas 37.85±7.61 and DOs 5.62. table 1 shows the inter-item correlation between the BIADL, BBS and SAS. This shows that there is no significant difference between the BI-ADL, BBS and SAS since p < 0.001. Table 3 shows a Cronbach's alpha of 0.87, which indicates a high level of internal consistency of the new tool.

Achievability of performance of activities:
The obtained results showed that 4.48% of the 26 activities expected to be performed were not achievable. An average of 43.98% of activities (i.e. touching specific point on SAB-U and placing the foot on specific point on SAB-L) was achievable but in more than 1.5 seconds. Only 51.53% of the 26 activities expected were achieved under 1.5 seconds (Table 4

and 5).
Abnormal synergy: From the results obtained it can be concluded that 44.23% of all participants had abnormal synergy present on either the upper limb or lower limb or both. this was calculated by computing the average of all percentages of abnormal synergy (table 6 and 7).  Achievability of performance of activities: the degree of achievability for both the upper limb and lower limb (Table 8 and 9) showed that, 4.17% of the 26 activities expected to be performed were not achievable (score 0). An average of 44.67% of activities was achievable but in less than 1.5 seconds (score 1). Only 51.24% of the 26 activities expected were achieved less than 1.5 seconds (score 2).
Abnormal synergy: results obtained showed that at 46.88% of all participants in Group 2 had abnormal synergy present on either the upper limb No 10 76.9 10 76.9 10 76.9 10 76.9 10 76.9 10 76.9 10 76.9 10 76.9 10 76.9  or lower limb or both (Table 10 and 11). This was calculated by computing the average of all percentages of abnormal synergy. Achievability of performance of activities: the degree of achievability for both the upper limb and lower limb (Table 12 and 13) showed that, 5% of the 26 activities expected to be performed were not achievable. An average of 48.48% of activities were achievable but in less than 1.5 seconds. Only 46.52% of the 26 activities expected were achieved in less than 1.5 seconds. the above overall achievability was calculated by computing the mean value of all activities with score 0, 1 and 2 respectively.
Abnormal synergy: the results obtained showed that 40% of all participants in Group 3 had abnormal synergy present on either the upper limb or lower limb or both. this was calculated by com-puting the average of all percentages of abnormal synergy (Table 14 and 15).       tained result showed that the new tool is internally consistent and reliable. the new tool also showed good correlation with BBS and BIADL using the inter-item correlation matrix. this tool may serve as an alternative tool to assess balance and activities of daily living but should be subjected for further studies.
cONcLUsION the synergy assessment chart and board was developed to assess abnormal synergy in the upper limb and lower limb. it creates an alternative to assessing synergy pattern among stroke survivors. With results obtained from analysis the new tool showed good reliability.
When correlated with standardized tools -the Berg balance scale and Barthel index of activity of daily living, it showed that there was no significant difference between the synergy assessment scale, the Berg balance scale and the Barthel index of activity of daily living scale. it can be assumed that the SAC and SAB can be used to assess activity of daily living and balance of stroke survivors.