therefore , moderate exercise or 
 training and appropriate maintenance are critical . for those with impaired limbs , it is more 
 crucial to perform proper reasonable rehabilitation training to restore normal daily 
 function .
most human physical actions involve using the hands . according to reports from the u.s . 

national security agency , one - third of occupationally impaired body functions affect the 
 upper limbs1 . in its functional disability 
 standards
, the american medical association identifies that losing one arm is equal to 
 losing 60% of the body mechanisms .
the loss of a hand equates to the loss of 90% of the arm 
 function or 54% of the entire body mechanism2 ; having healthy upper limbs is a matter not to be ignored .
usually , patients with an upper limb dysfunction need to be trained repeatedly using 
 appropriate rehabilitation equipment to recover .
clinically some of the most frequently used 
 equipment include exercise skate of the arm , exercise skate of the hand , vertical tower , 
 incline board , stacking cones and cura motion exercises .
there are many therapeutic methods 
 such as mechanical arms ( passive or positive patient training through mechanical 
 structures)3,4,5,6,7,8 , video games ( follow the instructions on the screen to move 
 mechanical arms to help neural rehabilitation)9 , and virtual reality ( integrate and improve sound , video , graphics , 
 and text ) to make users feel they are experiencing it for real10,11,12,13,14 .
the shoulder joint is frequently used in daily activities , making it prone to sprain and 
 bruising , causing shoulder rotation or abduction disorders .
patients decrease the shoulder 
 joint mobility because of the fear of pain , thereby affecting damaged function 
 reconstruction . shown in fig .
1.traditional training activities is a traditional shoulder training activity called the shoulder finger ladder , which 
 strengthens and increases the shoulder angle movement using finger movements .
patients face 
 a wall ( front and side ) and move the fingers of the affected side upward along the ladder to 
 their maximum reach .
the arm of the affected side is used to move a 
 plastic piece from the left to right or from the right to left to train the initiation 
 movement .
traditional training activities researchers are motivated to introduce virtual reality concepts to traditional 
 rehabilitation training as it increases patient enthusiasm and repeatability .
the primary 
 goal of this research was to train the upper limbs . to facilitate participants using this 
 training in daily life , researchers applied the microsoft kinect somatosensory devices ( for 
 windows ) for the 3d human motion capture system .
this system detects human skeleton 
 coordinates such as the palms , wrists , and both shoulders to develop unity games . 

participants can be trained through these games and scenes on the screen without actually 
 having to touch a real entity .
this study used mission - oriented training in applying kinect 
 somatosensory device software development with unity 3d games to enhance the training 
 effects .
this approach is very convenient and safe because participants only need to touch 
 the assigned virtual objects using their upper extremity .
argued that the kinect - based 3d reachable workspace analysis provides 
 sufficiently accurate and reliable results compared to motion capture systems , and that 
 proposed methods could be promising for the clinical evaluation of upper extremity in 
 neurological or musculoskeletal conditions15 .
training using video games played on the xbox kinect may be an 
 effective intervention for the rehabilitation of stroke patients16 .
unity 3d is a low price , powerful , and intuitive game 
 engine applied widely in industry .
even though it can be used to develop games it does not 
 support a somatosensory application .
kinect 
 is designed to detect human skeleton information which is the key to developing 
 somatosensory games .
the signals are captured and transmitted to unity 3d through microsoft 
 sdk ( kinect for windows sdk ) or open ni ( open nature interaction ) to drive the game 
 character actions .
figure 2fig . 2.overall scheme of the rehabilitation system , ( a ) computing angle of shoulder 
 joint shows the overall schematic diagram of this study .
human skeletons were displayed in 
 action on a pc using windows sdk , the unity 3d software tool , and the kinect s sensing 
 device .
since the 
 kinect senses human skeleton data , this 3d coordinate data must be projected to the 
 corresponding unity3d s virtual scenes on the pc screen .
the virtual scenes can be used to 
 construct and plan game scenes or express different design collision effects .
the hardware 
 interface used microsoft s product and the kinect hardware for windows to connect to the 
 computer .
the advantage of the kinect is that its skeleton recognition technology can be 
 used to determine actions while other relevant action information capture technology is 
 captured through the physical installation of many sensing elements and cables . the 
 development interface and application program part is mainly composed of the installation of 
 drivers for the kinect for windows sdk and unity3d software .
common programming language c # 
 between these two was used to write a program , the game application was produced using the 
 compilation and function calls of the kinect sdk through unity3d .
this program could be used 
 to measure data while the game was running , as well as recorded the 3d coordinates of the 
 skeleton of the participants during the training process .
overall scheme of the rehabilitation system , ( a ) computing angle of shoulder 
 joint to capture human skeleton coordinates via the kinect device , the angles could be measured 
 by the bones that connect to the joints , and the angle differences in movements can help 
 medical workers understand the accuracy of poses and action changes for patients in the 
 process of training activities .
figure 2 ( a ) shows 
 the collected data for the shoulder , elbow , and wrist joint coordinates , which were 
 s(sx , sy , sz)e(ex , ey , ez)w(wx , wy , wz ) the elbow angle formula was figure 3(a)fig .
3.design of the motion trajectory ( take right hand as an example ) shows the training activities in the frontal plane  the shoulder finger ladder design 
 used as training for upper extremity lifting or measurement purposes .
the bottom is the 
 reference ( ref ) , the rectangular areas are reminders for the participants to touch a virtual 
 position ( represented by the letters from a 
the red rectangular area ( figure marked as a ) is used for participants to touch 
 according to the ref ( the very bottom of the figure ) upon completion of the designated touch 
 order ( shown as a step ) .
the patient virtually touched the point with their hands . at the same 
 time , the red rectangular area automatically moves on the screen to show the completion of one 
 round as soon as the participants have completed a 
design of the motion trajectory ( take right hand as an example ) the following contains the explanation for each  ladder  planned for the shoulder finger 
 ladder .
the subject stands in front of the kinect device at the start with their body captured 
 completely .
the captured coordinate data for the head , spine , hip center , elbow , wrist joint 
 were 
 h(hx , hy , hz)s(sx , sy , sz)hc(hcx , hcy , hcz)e(ex , ey , ez)w(wx , wy , wz ) .
the ref position is defined as : h(hx , hy* , hz* ) , 0.5 <  < 0.95 , 0.75 <  < 1 the related positions are defined by the ref on the starting position ( pos_min ) of the 
  ladder  : s(sx , sy , sz* ) , 0.75 <  < 1 the ending position ( pos_min ) of the  ladder  is : hc(hcx , hcy , hcz)* ) , 0.75 <  < 1 adjacent to the  ladder  is the gap ( if the area is divided into k ) : figure 3(b ) shows the training activities in the 
 frontal plane  the planned design for the single curved shoulder .
the subject sequentially 
 touched the objects virtually from the left side of the hand toward the right , clockwise and 
 then in the counterclockwise direction to the original starting point .
this activity trained 
 the shoulder , elbow , and forearm and was very helpful for hand - eye coordination and reaction 
 cultivation .
patients with frozen shoulders were trained with the shoulder finger ladder and the single 
 curved shoulder training activities combined .
point of the shoulder finger ladder 
 activity could be the radius of curvature the single curved shoulder activity which provided 
 better protection for the subject in the safety training process .
this experiment was performed in two parts : one for those with normal shoulder function and 
 the other for those with shoulder disability .
the participants used their hands according to 
 the indicator points on the screen to virtually complete the exercise ; the computer system 
 recorded the coordinates and performed the statistical analysis , which can be referenced by 
 clinic personnel later on . to confirm the reproducibility and stability of the system 
 development , it was very helpful to understand whether this system was stable enough for 
 clinical training activities for assessing and analyzing the test results from participants of 
 different ages and body types or the same participant with various testing times17 , 18 . in the normal shoulder function group ,
8 participants conducted 12 rounds of training and 
 testing with the device developed in this study .
the collected training data were analyzed to 
 examine the variations before and after the training to determine whether the system could 
 provide consistent evaluations of the usually used hand , and to make sure that the system was 
 stable with high repeatability . in the shoulder disability group , there were 4 participants 
 conducting training for 6 weeks ( twice a week ) , with 3 rounds of practice and 3 minutes of 
 rest between each round .
the ethical 
 committee at the taipei medical university hospital approved the study , and written informed 
 consent was obtained from each participant .
eight subjects ( age range 2130 , 3140 , 4150 , 5160 ; 2 subjects in each group ) with normal 
 shoulder function were chosen to perform the shoulder finger ladder and the single curved 
 shoulder exercise 12 times ( 3 rounds in each practice ) of the training and testing to check 
 reproducibility and stability .
4.the performance of subject a-1 ( left handed ) in the shoulder finger ladder test shows the single curved shoulder test screen of the subjects .
it shows that the 
 subjects raised their right hand to touch the object ( red ) on the oval .
figure 4(b ) shows the performance of subject a-1 ( left handed ) in 12 
 exercises .
the left and right - hand average usage time reached stability at approximately up 
 to 33.5sec and 41.2 seconds in the seventh and ninth test , respectively .
the total average 
 usage time for the left and right hand was 35.4 ( sd = 2.35 ) and 42.8 ( sd = 1.60 ) seconds , 
 respectively .
the results indicate that dominant side movement is more flexible than the 
 non - dominant side .
the performance of subject a-1 ( left handed ) in the shoulder finger ladder test table 1table 1.the performance record of 8 subjects with normal shoulder functionyear groupsubject / genderdominant sideaverage using time ( sec)shoulder finger laddersingle curved shoulderleft handright handleft handright hand2130a-1/male / left hand21.60.823.90.835.42.442.82.6a-2/female / right hand23.90.822.40.743.02.335.12.23140b-1/female / left hand23.40.825.10.938.12.243.92.7b-2/male / right hand25.40.923.10.844.62.837.42.34150c-1/male / left hand25.10.828.60.940.22.648.12.6c-2/female / right hand29.10.925.30.950.12.841.42.75160d-1/male / left hand27.01.032.91.645.23.349.42.9d-2/female / right hand32.21.726.91.051.22.943.63.3 shows the performance record of 8 ( 4 age groups ) subjects with normal shoulder 
 function
. the results indicated that the average usage time for the dominant side of the 
 subjects in the same age group were close to the shoulder finger ladder and single curved 
 shoulder activity ; indicating good system stability .
the average usage time for both hands 
 indicated that the dominant side movement is more flexible than the weak side .
moreover , the 
 flexibility and ability to respond in elders were slightly inferior to that of the younger 
 groups .
the study included 4 subjects with impaired shoulders who participated in the test ; the 
 basic information of these subjects are shown in table 
 2table 2.basic information of the 4 subjects with impaired shouldersubjectagegenderdominant side / affected sidesymptomsp-153maleright / rightsports injuryp-248maleright / rightfrozen shoulderp-355femaleleft / leftfrozen shoulderp-467maleright / lefttraffic accidentp-546femaleright / rightvocational injuryp-663maleleft / righttraffic accident . table 3table 3.result of the  shoulder finger ladder  and  single curved shoulder  test on the 
 affect sidetypesubjectaverage using time ( sec)wk 12wk 34wk 56shoulder finger ladderp-132.91.928.41.127.50.1p-235.72.032.11.431.30.4p-336.01.932.61.331.60.3p-439.82.436.52.035.01.0p-533.12.331.91.931.00.2p-639.22.836.22.935.10.9single curved shoulderp-166.519.548.97.647.50.1p-268.918.553.812.352.91.3p-369.217.254.010.353.81.0p-478.718.768.69.967.41.3p-567.619.851.911.151.21.1p-677.117.667.19.166.31.2value are expressed as mean  sd displays the result ( average using time ) of the 6 subjects ( p1p6 ) during the 
 entire test period of the shoulder finger ladder and the single curved shoulder presented in 
 a bi - week interval .
every subject s performance showed positive results in the mid - stage , 
 and stability in the post - stage .
value are expressed as mean  sd to assess the average performance time of subjects in the 6 week test trial , researchers 
 set the benchmark as the average score of tests given 4 times biweekly .
researchers 
 performed pairwise statistical tests ; see table 
 4table 4.result of the statistical test ( pairwise)typesubjectbetween the weekswk 12 / wk 34wk 34 / wk
56wk 12 / wk 56shoulder finger ladderp-132.9/28.4 * 28.4/27.532.9/27.5*p-235.7/32.1 * 32.1/31.335.7/31.3*p-336.0/32.6 * 32.6/31.636.0/31.6*p-439.8/36.5 * 36.5/35.039.8/35.0*p-533.1/31.9 * 31.9/31.033.1/31.0*p-639.2/36.2 * 36.2/35.139.2/35.1*single curved shoulderp-166.5/48.9 * 48.9/47.566.5/47.5*p-268.9/53.8 * 53.8/52.968.9/52.9*p-369.2/54.0 * 54.0/53.869.2/53.7*p-478.7/68.6 * 68.6/67.478.7/67.4*p-567.6/51.9 * 51.9/51.267.6/51.2*p-677.1/67.1 * 67.1/66.377.1/66.3**paired - t test , p<0.05 for the results .
the first and second weeks were adjusted for the stage for 
 all subjects , however , the performance was not ideal .
there was a significant improvement in 
 the third - fourth and the fifth - sixth weeks .
the t - test results comparing 12 weeks to 34 
 week and 12 weeks compared to 56 weeks showed a significant difference .
the average 
 performance reached stability after the third week , and there was no significant difference 
 in the t - test results at 34 weeks and 56 weeks .
the results indicated that this system was 
 effective in the training of each subject . *
the shoulder joint has the largest range of motion , the most complicated action form and is 
 the most frequently used joint in physical activities , resulting in a higher injury 
 frequency .
this study used the 
 kinect somatosensory device with unity software to develop 3d situational games for upper 
 extremity training activities .
using games as training methods helps improve concentration , 
 patient interest in participation , and helps patients temporarily forget about their body 
 discomfort .
the equipment used in this study is inexpensive , easy to obtain and the system 
 is easy to install .
our 
 group will continue to recruit more cases with impaired upper limb function to conduct 
 related research and develop suitable rehabilitation training games . to have more effective 
 methods ,
researchers have introduced games and virtual reality training to help participants 
 train their upper limbs in a relaxed environment .
 [ purpose ] researchers imported games and virtual reality training to help participants 
 train their shoulders in a relaxed environment . 
 [ subjects and methods ] this study included 
 the use of kinect somatosensory device with unity software to develop 3-dimensional 
 situational games . 
 the data collected from this training process can be uploaded via the 
 internet to a cloud or server for participants to perform self - inspection . 
 the data can be 
 a reference for the medical staff to assess training effectiveness for those with 
 impairments and plan patient rehabilitation courses . 
 [ results ] in the training activities , 
 8 subjects with normal shoulder function demonstrated that the system has good stability 
 and reproducibility . 
 six subjects with impaired shoulder underwent 6 weeks of training . 
 during the third week of training , 
 average performance stabilized . 
 the t - test comparing 
 12 weeks to 34 weeks and 56 weeks showed significant differences . 
 [ conclusion ] using 
 games as training methods improved patient concentration , interest in participation and 
 allowed patients to forget about their body discomfort . 
 the equipment utilized in this 
 study is inexpensive , easy to obtain , and the system is easy to install . 
 people can 
 perform simple self - training both at home or in the office . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION