muscle activation varies according to the size and shape of the driver s hand 
 grip1,2,3 and it affects the amount of discomfort and 
 fatigue they experience while they are driving . most of them use a 
 spinner knob with their non - affected hand instead of a steering wheel . a spinner knob helps 
 a driver control the steering wheel with only one hand . . 
 however , there is a lack of research about analyzing the driving performance of drivers who 
 have had a stroke . therefore , the purpose of this study was to investigate the muscle 
 activates of drivers with post - stoke hemiplegia while driving using a steering wheel and a 
 spinner knob , and compare them with those of non - disabled drivers . while 10 participants were originally selected for this study , a total of nine drivers 
 participated in this experiment : five drivers with post - stroke hemiplegia ( experimental 
 group ) and four non - disabled drivers ( control group ) . the stroke group did not have any 
 neurological , musculoskeletal , cognitive , or perceptual problems except for the stroke . in 
 terms of driving history , they had been driving for more than three years after they had a 
 stroke . the control group consisted of four drivers of a similar age and gender as the 
 experimental group . however , one driver in the control group elected to drop out of the 
 study during the experimental process . this study was conducted with 3 males and 2 females 
 in the experimental group and 3 males and 1 female in the control group . the average height 
 of the experimental group was 163.5  cm , and that of the control group was 162.75  cm , and 
 their average weights were 60.75 and 59.25  kg , respectively . the average driving experience 
 of the experimental and control groups was 15  years and 6 months , and 14  years and 5 months , 
 respectively . the subjects participated in this study after receiving an explanation of 
 purpose of this study and had signed a consent form . the driver s seat 
 angle was 1055 and the height of the seat 
 was 20.8 inch6 . a researcher adjusted the 
 distance between the driver and the steering wheel to maintain a 113 angle of the elbow 
 when the participant held the steering wheel at a 30 angle to the right from the 
 midline7 ( fig . a spinner knob was set at an angle 30 clockwise from the center of the upper part 
 of the steering wheel because the drivers in the experimental group had post stroke , left 
 side hemiplegia . the speed limit was at least 10  km / h but not more than 20  km / h . the 
 experimental task consisted of driving forward in a straight line for 5 m , turning right or 
 left , and driving straight ahead for another 5  m. the participants in the experimental group 
 and the control group were instructed to only use either the steering wheel or the spinner 
 knob with only their right hand . muscle activities were measured using surface emg ( telemyo 2400 t g2 , noraxon 
 usa , inc . , the collected surface emg signals were converted into 
 digital signals by a telemyo 2400 t g2 , and the converted signals were processed using 
 myoresearch master xp 1.07 software . electrodes 
 were placed over the anterior deltoid , biceps brachii and triceps brachii on the right - side 
 according to the method suggested by mo et al8 . the emg data were converted to root - mean - square values that 
 provided values close to the actual output values of the emg signals . for quantification , the emg signal volumes as a percentage of the reference voluntary contraction ( % rvc ) were 
 measured . the reference voluntary contraction was measured in a sitting posture with the 
 knees and hips flexed at 90. before beginning the experiment , emg was measured when the 
 participant flexed the elbow and then flexed the shoulder , extending the elbow with a 2-kg 
 dumbbell in the hand . data were analyzed using spss 18.0 . to test the homogeneity of age , gender , driving 
 history , car model , and driver licenses classification between the experimental group and 
 the control group , the  test was performed . to compare activation of the three 
 muscles between the two groups , the mann - whitney u test was performed . to compare the muscle 
 activation between the spinner knob and the steering wheel by group , the results of the comparison of the activation of the three muscles between the steering 
 wheel and the spinner knob while the drivers in the experimental group turned the vehicle to 
 the left were as follows . there was no significant difference in the activation of the three 
 muscles between the spinner knob and the steering wheel when drivers in the experimental 
 group turned to the left . when the drivers in the experimental group turned to the right , a 
 significant difference in the activation of the muscles between the spinner knob and the 
 steering was found only in the biceps brachii . the activities of the three muscles between the steering wheel and the spinner knob when 
 the control group turned the vehicle to the left showed no significant differences . when the 
 control group turned the vehicle to the right , there were no significant differences in 
 activities of the three muscles between the spinner knob and the steering wheel . activation 
 of the biceps brachii while turning the vehicle to the right with the spinner knob was 
 significantly lower in the experimental group than in the control group ( table 1table 1.muscle activation during left and right turns made with a spinner knob and a 
 steering wheel ( n=10 ) ( unit : % rms)strokecontrolspinner knobsteering wheelspinner knobsteering wheelturning to the leftanterior deltoid27.19.127.25.235.011.738.312.5biceps brachii17.81.715.94.122.910.337.54.7triceps brachii22.310.020.39.138.83.636.66.7turning to the rightanterior deltoid25.85.626.13.931.212.732.916.7biceps brachii15.13.222.13.8 38.79.9 * 36.28.2triceps brachii22.98.126.916.341.817.242.718.4*significant difference between stroke group and control group at 0.05 level . as the number of drivers with post - stroke hemiplegia grows , driving rehabilitation becomes 
 more important . to help these drivers , occupational therapists need to analyze their driving 
 performance . the aim of this study was to investigate and compare muscle activation 
 differences between using a spinner knob and a steering wheel in drivers with post - stroke 
 hemiplegia and non - disabled drivers . the experimental group was comprised of five drivers 
 with post - stroke , left - side hemiplegia . because the required devices , driving position , and 
 other factors may vary depending on the affected side , this study included only drivers with 
 left - side hemiplegia . when the drivers in the experimental group turned the vehicle to the right using a steering 
 wheel or a spinner knob , the activation of the biceps brachii was significantly different . mo et al.8 reported that the biceps 
 brachii was activated when a vehicle was turned to the right , and the anterior deltoid and 
 the triceps were also activated when engaging in that movement . however , in this study , 
 activation of the triceps and the anterior deltoid was not observed . with regard to the 
 control motion of a spinner knob or a steering wheel when turning a vehicle to the right therefore , only activation of 
 the biceps brachii was found to be significantly different between using a steering wheel 
 and a spinner knob . it is interesting to note that activation of the biceps brachii was not 
 significantly different between using a steering wheel and a spinner knob in the control 
 group , unlike drivers in the experimental group . this shows that a spinner knob requires 
 less muscle activation than a steering wheel for drivers with stroke . the results of the comparison of the activation of the biceps brachii between the two 
 groups show that , the biceps activation in the drivers in the experimental group was lower 
 than that in the control group . this could be because four of the five drivers in the 
 experimental group usually used a spinner knob , while none of the drivers in the control 
 group used a spinner knob . adaptation might influence activation of the related muscles9 . because drivers with stroke have difficulty with bilateral hand use , a number of them use a 
 spinner knob instead of a steering wheel . occupational therapists must know how to analyze a 
 stroke patient s driving performance and understand how an adaptive driving device can help 
 them to drive safely . the results of this study indicate that a spinner knob requires less 
 activation of the main muscles than a steering wheel , especially in drivers who have had a 
 stroke . therefore , in the future , research 
 on the time it takes to adapt to using a spinner knob and other adaptive devices will be 
 needed . limitations of this study are that all the participants in the experimental group 
 were drivers with left hemiplegia , and the number of participants was insufficient to 
 generalize the results . although there was 
 a speed limit for the driving , the drivers could nt keep a consistent speed .
[ purpose ] the aim of this study was to investigate three muscle activities of drivers 
 with post - stoke hemiplegia while they were driving using a steering wheel or a spinner 
 knob , and to compare them with those of non - disabled drivers . [ subjects and methods ] the 
 subjects were four non - disabled drivers and five drivers with left hemiplegia . 
 the 
 subjects drove forward in a straight line for 5  m and then turned right or left using the 
 steering wheel or spinner knob with only their right hand . 
 emg electrodes were placed over 
 the anterior deltoid , biceps and triceps brachii on the right - side . 
 [ results ] while 
 differences in muscle activation between the spinner knob and the steering wheel in the 
 control group were not significant , those of the experimental group were significant . 
 activation of the biceps brachii while the control group turned the vehicle to the right 
 using the spinner knob was significantly lower than when using the steering wheel . 
 activation of the biceps brachii while the experimental group turned the vehicle to the 
 right using the spinner knob was significantly lower than that of the control group . 
 [ conclusion ] the results of this study indicate that a spinner knob requires less 
 activation of the main muscle than a steering wheel , especially in drivers who have had a 
 stroke . 
 the results could be used as basic data when driver rehabilitation specialists 
 prescribe the spinner knob for patients .