the participant of this study is a male subject ( 37 years old , 1.70 m , 67.40 kg and manual preference for right hand ) with complete sensory - motor thoracic traumatic spinal cord injury ( t9 ) , ais a ( american spinal injury association impairment scale ) and with 3 years post - sci .
he is a manual wheelchair user who is capable to perform a spt without physical or technical assistance , routinely using this type of transfer in daily life for both sides ( right / left ) .
additionally , he does not have any condition that affects the ability to transfer or the use of electrical stimulation .
the spt were performed by the participant using two seats with the same characteristics ( 42 cm x 42 cm ) and with an angle of 20 between them .
the height of both seats ( 48 cm ) resembles that of the wheelchair used by the participant . beneath each seat , a force plat ( bertec corporation ; columbus , ohio )
additionally , another force plat was placed beneath the participant s feet , so the force caused by the stimulation could be also recorded .
the seats were firmly attached to a wooden case placed between the seats and the force plates .
the additional weight imposed by the seats and the wooden structure was compensated by software before running the experiments .
kinetic data were recorded with a sampling frequency of 200 hz . the bilateral femoral quadriceps ( rectus femoral ) of the participant were electrically stimulated ( hasomed , rehastim ) by surface electrodes with the following parameters : frequency of 50hz and pulse width of 450s , while the intensity varied according to the desired muscle contraction grades from the manual muscle test ( mmt ) .
the intensity levels were identified while the individual was sitting on his wheelchair : 38ma to reach grade 3 in mmt ; 48ma to reach grade 4- in mmt ; 52ma to reach grade 4 in mmt .
the parameters were tested in the individual before running the spt experiments . the start and stop of fes
the participant was encouraged to use his usual transfer strategy during the experiments . after a familiarization period ,
figure 2 shows the force data of the three force plates during the spt for both scenarios : with and without fes .
force plates 1 and 3 correspond to the ones placed beneath each seat , while force plate 2 recorded the feet reaction forces .
the force data was normalized to the participant body weight and the time was expressed as a percentage of the total movement time , corresponds to the total trial duration .
the participant performed a total of eight trials with fes and four trials without fes .
the trials chosen for analysis correspond to the ones in which the individual had the best performance in the spt , based on some conditions verified through video documentation : transfer performed on the same side , hand maintenance in the same position along the transfer and a single lift movement with respect to the pelvis motion . according to the analysis of the video recorded for each trial , the best performance of the spt was when the participant transferred from the left to the right side , therefore three trials with fes and two without fes were selected for further analysis . in this study the spt division is the same as the one used in previous works .
hence , the pivot transfer is defined by the occurrence of three phases : pre - lift , lift - pivot and post - lift . for this preliminary study ,
only the force information was used to delimit the beginning and the end of each phase .
the beginning of the pre - lift and the end of the post - lift , which delimit the overall transfer motion were determined by the start and the end of motion dynamics looking at the forces provided by the force plates 1 and 3 , while the lift pivot resultant takes place when the resultant force of plate 1 starts to decrease ( after attaining a certain threshold ) and ends when the resultant from the force plate 3 reaches its maximum value .
figure 3 shows the transfer motion selected by each trial according to the lift - pivot phase detection explained above . in order to assess the effect of the fes during the spt based on the force data from the three platforms , a calculation of the force impulse ( the integral of force over time ) for the resultant forces during the lift - pivot phase
the idea of this calculation is to use this parameter to quantify the effect of fes on the ll .
if the fes is capable to provoke a force on the ll , then the total force during the transfer will increase on the data recorded from force plate 2 when compared to the trials without fes .
the force impulse of the rest of the plates should be the same or , in the best scenario , will decrease as a positive effect of the fes in aiding the subject to perform the spt .
the participant of this study is a male subject ( 37 years old , 1.70 m , 67.40 kg and manual preference for right hand ) with complete sensory - motor thoracic traumatic spinal cord injury ( t9 ) , ais a ( american spinal injury association impairment scale ) and with 3 years post - sci .
he is a manual wheelchair user who is capable to perform a spt without physical or technical assistance , routinely using this type of transfer in daily life for both sides ( right / left ) .
additionally , he does not have any condition that affects the ability to transfer or the use of electrical stimulation .
the spt were performed by the participant using two seats with the same characteristics ( 42 cm x 42 cm ) and with an angle of 20 between them .
the height of both seats ( 48 cm ) resembles that of the wheelchair used by the participant . beneath each seat , a force plat ( bertec corporation ; columbus , ohio )
additionally , another force plat was placed beneath the participant s feet , so the force caused by the stimulation could be also recorded .
the seats were firmly attached to a wooden case placed between the seats and the force plates .
the additional weight imposed by the seats and the wooden structure was compensated by software before running the experiments .
kinetic data were recorded with a sampling frequency of 200 hz . the bilateral femoral quadriceps ( rectus femoral ) of the participant were electrically stimulated ( hasomed , rehastim ) by surface electrodes with the following parameters : frequency of 50hz and pulse width of 450s , while the intensity varied according to the desired muscle contraction grades from the manual muscle test ( mmt ) .
the intensity levels were identified while the individual was sitting on his wheelchair : 38ma to reach grade 3 in mmt ; 48ma to reach grade 4- in mmt ; 52ma to reach grade 4 in mmt .
the parameters were tested in the individual before running the spt experiments . the start and stop of fes
the participant was encouraged to use his usual transfer strategy during the experiments . after a familiarization period ,
figure 2 shows the force data of the three force plates during the spt for both scenarios : with and without fes .
force plates 1 and 3 correspond to the ones placed beneath each seat , while force plate 2 recorded the feet reaction forces .
the force data was normalized to the participant body weight and the time was expressed as a percentage of the total movement time , corresponds to the total trial duration .
the participant performed a total of eight trials with fes and four trials without fes .
the trials chosen for analysis correspond to the ones in which the individual had the best performance in the spt , based on some conditions verified through video documentation : transfer performed on the same side , hand maintenance in the same position along the transfer and a single lift movement with respect to the pelvis motion . according to the analysis of the video recorded for each trial , the best performance of the spt was when the participant transferred from the left to the right side , therefore three trials with fes and two without fes were selected for further analysis . in this
hence , the pivot transfer is defined by the occurrence of three phases : pre - lift , lift - pivot and post - lift . for this preliminary study ,
only the force information was used to delimit the beginning and the end of each phase .
the beginning of the pre - lift and the end of the post - lift , which delimit the overall transfer motion were determined by the start and the end of motion dynamics looking at the forces provided by the force plates 1 and 3 , while the lift pivot resultant takes place when the resultant force of plate 1 starts to decrease ( after attaining a certain threshold ) and ends when the resultant from the force plate 3 reaches its maximum value .
figure 3 shows the transfer motion selected by each trial according to the lift - pivot phase detection explained above . in order to assess the effect of the fes during the spt based on the force data from the three platforms , a calculation of the force impulse ( the integral of force over time ) for the resultant forces during the lift - pivot phase
the idea of this calculation is to use this parameter to quantify the effect of fes on the ll .
if the fes is capable to provoke a force on the ll , then the total force during the transfer will increase on the data recorded from force plate 2 when compared to the trials without fes .
the force impulse of the rest of the plates should be the same or , in the best scenario , will decrease as a positive effect of the fes in aiding the subject to perform the spt .
the total duration of spt varies between 1.43 s to 2.45 s , while the lift pivot phase in trials 1 , 2 , 3 , 4 , and 5 corresponds to 57% , 64% , 69% , 68% and 45% of the total spt , respectively ( see table 1 ) .
the overall movement pattern was similar in all trials ( figure 2 ) with the resultant force changing from plate 1 to 3 .
a closer analysis of only the lift phase of the spt ( figure 3 ) reveals some differences between the spt with and without fes .
specifically , the force values in platform 2 are higher in trials 3 , 4 and 5 , compared to trials 1 and 2 .
no differences in terms of force amplitude were observed on platforms 1 and 3 for all trials .
figure 4.a and 4.c show the results for the impulse in all platforms , as a stacked bar chart , in body weight units and normalized by the total amount of impulse in all the platforms .
the calculation of impulse just for force plate 2 ( ll forces ) is also displayed on figures 4.b and 4.d .
, there is no study in the literature that uses the fes to assist the spt , so it is not possible to compare our data with any other previous study .
the total time of spt are similar to that shown by gagnon et al . ranging on average from 1.65 to 2.6
s , so fes did not modify the total transfer time , demonstrating that can be a good resource that does not affect the agility during the paraplegic transfer .
this is important to be considered , because if the assistive technology device in potential increases the total transfer time , it will not be practical on daily activities and the individual may have some resistance to use it .
found that the lift pivot phase has an average duration of 40% of the total spt cycle . in our experiments ,
the closest value was found in the fes trial with the highest intensity ( trial 5 ) .
it seems that a higher stimulation intensity reduces the lift phase duration , which in turn may reduce ul overload . in more a detailed study of the lift pivot phase
it is observed that the higher the current intensity of fes , the higher the muscular strength and greater the impulse on plate 2 .
this may indicate that the degree 4- in mmt of quadriceps muscle with fes is a good intensity to assist spt . this threshold will be better studied when the research sample is enlarged .
additionally , the use of fes did not hinder the spt movement and there were no clear negative effect , according to our preliminary analysis .
the kinetics curves in figure 3 indicate an increase in forces applied by the ll in the spt during the trials with fes activation , which means that the muscular activity induced by the fes was converted into forces that may have a positive effect during the spt favoring the movement . during the lift - pivot phase
therefore , the increase of the participation of the ll in the total impulse during the lift - pivot phase , as displayed in figure 4 is an indication of alleviated effort in the ul .
we need to investigate more if the increase of fes will produce a better participation of ll and a lower muscular demand of shoulder joint muscles , as well as a decrease impingement of the subacromial structures , which may minimize the risk of the joints during transfers .
physiotherapists and occupational therapists have little knowledge and clinical resources to assess spt in clinical practice .
there are few studies of this ability and little progress has been made in this area of expertise over the past years .
the sliding board is the unique low cost assistive technology resource used worldwide , but few progresses have been made on new technological possibilities in this area .
fes can be a potential alternative since it can be portable , lightweight , personalized and easy to use with surface electrodes .
this study shows some evidence that fes of quadriceps may favor participation of ll during spt , but the hypothesis that fes in ll decreases overload on ul should be further investigated in future studies .
 transfer is a key ability and allows greater interact with the environment and social participation . 
 conversely , paraplegics have great risk of pain and injury in the upper limbs due to joint overloads during activities of daily living , like transfer 
 . the main goal of this study is to verify if the use of functional electrical stimulation ( fes ) in the lower limbs of paraplegic individuals can assist the sitting pivot transfer ( spt ) . 
 the secondary objective is to verify if there is a greater participation of the lower limbs during lift pivot phase . 
 a preliminary study was done with one complete paraplegic individual . 
 temporal parameters were calculated and a kinetic assessment was done during the spt . 
 the preliminary results showed the feasibility of fes for assisting the spt . 
Material and Methods
Participant
Experimental Set Up
Data Analysis
Results
Discussion