the tilt table has the advantages of passive standing and improvement of renal function and 
 circulation , including prevention of joint contracture , muscle atrophy , and 
 osteoporosis1,2,3 . by controlling the degree 
 of tilt , the tilt table can be useful to initial weight bearing training of orthopedic 
 patients who require partial weight bearing or are unable to support their full body weights 
 due to lower limb injury or neurological damage . in particular , orthopedic patients with uncemented total hip arthroplasty , fracture , or 
 osteotomy are often instructed to bear partial weight on their injured or postoperative 
 lower limb4,5,6,7 . the common level of partial weight bearing training prescribed by 
 the orthopedic surgeon ranges from 20% to 50% of the patient s entire body weight8 . however , a previous partial weight bearing study reported that the operated lower limb was 
 actually loaded higher than the prescribed partial weight bearing during standing or 
 walking9 . hence , accurate information 
 regarding the exerted weight distribution on the lower limb is necessary for orthopedic 
 patients with restrictions of body weight bearing . although the tilt table is useful in clinical practice , there has been no research into the 
 weight distribution of the lower limb according to different angles of inclination during 
 tilt table standing . therefore , the purpose of this study was to measure the amount of 
 weight bearing on the lower limb during tilt table standing and to indicate the ideal degree 
 of tilting for partial weight bearing of orthopedic patients with restrictions of body 
 weight bearing . seven healthy male subjects and eight female subjects between the ages of 20 and 30 were 
 recruited as volunteers for this study . the baseline demographic characteristics of the 
 subject enrolled in this study were as follows : the mean age , height , weight , and foot 
 length of the subjects were 25.12.6  years , 165.36.8  cm , 61.17.8  kg , and 248.014.6  mm , 
 respectively . subjects were excluded if they had a diagnosed neurologic disease or disorder 
 or a musculoskeletal problem in a lower limb . all subjects understood the purpose of this 
 study and provided informed consent prior to participation in the study in accordance with 
 the ethical standards of the declaration of helsinki . tilt table standing was performed on a motorized tilt table , the incline angle of which 
 could be adjusted in the range of 90 to 8 degrees ( og giken co. , ltd , okayama japan ) . subjects laid their back on the tilt table and were positioned with both foot flat and 
 neutrally against the foot plate . velcro straps at the knees and hips were used to stabilize 
 the subject in an upright position . target angles of tilt table standing for measuring 
 plantar pressures were 0 , 30 , 60 , and 90 degrees , respectively , and each angle was sustained 
 for 1 minute with autonomic data collection . plantar pressures were measured using an f - scan system ( tekscan , south boston , ma , usa ) . the pressure was recorded at 50  hz for 4 seconds with a pressure - sensitive insole consisting 
 of a 0.15-mm - thick sensor with an embedded grid of 960 pressure - sensing cells that were 
 evenly distributed at a 0.5-cm interval . the sensor was connected to a cable , and data were 
 transmitted through the cable to a portable computer . for the test , the subjects wore their own shoes and were fitted with the portable equipment 
 and the pressure sensitive insoles described below , which were trimmed to their shoe size . the f - scan system was calibrated to adjust for the subject s body weight before each 
 measurement . all the measurements were taken with the subjects standing on the tilt table 
 according to different inclination angles . after the pressure was read and recorded , data 
 were processed and averaged with custom - made software , f - scan version 4.19f . to compare the plantar pressures according to different degrees of tilting , the pressures 
 at 90 of tilt table standing were interpreted to a standardized weight bearing ( full weight 
 bearing ) , and the feet were divided into the dominant and non - dominant side . general 
 characteristics ( age , sex , height , weight , and foot length ) of subjects were obtained using 
 frequency analysis and descriptive statistics . repeated measures anova was performed to 
 estimate differences in plantar pressures among four different tilting degrees . comparison of mean plantar pressure distributions of the four different angles 
 of tiltparameters0 ( 95%ci)30 ( 95%ci)60 ( 95%ci)90 ( 95%ci)cp(%tbw)*ds11.40.9 ( 9.413.4)29.62.1 ( 25.134.0)38.91.5 ( 35.842.1)47.81.5 ( 44.551.0)*nds12.91.0 ( 10.65.1)32.22.1 ( 27.736.6)44.31.6 ( 41.047.8)52.21.5 ( 49.055.5)pcp(%tbw)*ds8.70.8 ( 7.110.3)28.51.8 ( 24.632.5)40.62.1 ( 36.045.2)48.31.7 ( 44.752.0)*nds10.30.9 ( 8.312.3)32.01.9 ( 28.036.0)45.41.9 ( 41.249.5)51.71.7 ( 48.155.3 ) * significant difference ( p<0.01 ) . cp , contact pressure ; pcp , peak contact 
 pressure ; tbw , total body weight ; ds , dominant side ; nds , non - dominant sidetable 2 . multiple comparisons of plantar pressure distributions of each angle of 
 tiltparameters(i ) degree(j ) degreemd ( ij)cp ( % tbw)ds030*19.260*28.590*37.03060*9.390*17.86090*8.5nds030*20.260*32.790*40.33060*12.590*20.16090*7.6pcp ( % tbw)ds030*20.460*32.290*40.13060*11.890*19.76090*7.9nds030*22.060*35.890*42.33060*13.890*20.36090*6.5 * significant difference ( p<0.01 ) . cp , contact pressure ; pcp , peak contact 
 pressure ; tbw , total body weight ; ds , dominant side ; nds , non - dominant side ; md , mean 
 difference show the contact and peak contact pressures of the dominant and non - dominant 
 feet according to different degrees of tilting . the contact pressure of each side during tilt table 
 standing at 60 was lower by 89% of total body weight than during tilt table standing at 
 90 , and the contact pressure at 30 was lower by 1820% of total body weight than during 
 tilt table standing at 90. * significant difference ( p<0.01 ) . cp , contact pressure ; pcp , peak contact 
 pressure ; tbw , total body weight ; ds , dominant side ; nds , non - dominant side * significant difference ( p<0.01 ) . cp , contact pressure ; pcp , peak contact 
 pressure ; tbw , total body weight ; ds , dominant side ; nds , non - dominant side ; md , mean 
 difference the peak contact pressure during tilt table standing at 60was lower by 68% of total body 
 weight than during tilt table standing at 90 , and the peak contact pressure at 30 was 
 lower by 1920% of total body weight than during tilt table standing at 90. if a patient needs partial weight bearing training , a physiotherapist should educate the 
 patient regarding performance of partial weight bearing at the prescribed target load . accurate information regarding the exerted weight distribution on the lower limb is 
 necessary for orthopedic patients with restrictions of body weight bearing . physical 
 therapists utilize clinical techniques , such as tactile feedback , as well as several 
 devices , such as scales , biofeedback systems , and force plates , to train patients who 
 require partial weight bearing10,11,12,13 . however , it is difficult to stand 
 independently in the early stages of an injury or after surgery , and the cost of equipment 
 may limit clinical application of partial weight bearing . early weight bearing in patients 
 with the lower limb injury would diminish the risk of postoperative complications , such as 
 deep venous thrombosis and stiffness , and provide safer recovery to a pre - fracture 
 ambulation level14 . thus , the tilt table 
 can help efficiently in early partial weight bearing training , and it can maintain a 
 constant the identical amount of weight bearing according to different angles of 
 inclination . our results indicated that the contact and peak contact pressures of each side during tilt 
 table standing at 60 were lower by 79% of total body weight than the pressures during tilt 
 table standing at 90 , and they were lower by 1820% of total body weight than the pressures 
 during tilt table standing at 90. if the plantar pressures of the dominant or non - dominant 
 sides during tilt table standing at 90 are interpreted to a full weight bearing , the weight 
 bearing of each side during tilt table standing at 60 would be 80% of full weight bearing 
 and that at 30 would be a 60% of full weight bearing . our findings are supported by the 
 previous study of kim et al.15 , who 
 reported that the larger the tilting degree of the tilt table , the greater the 
 electromyographic activity exerted on the lower limb . yuk s study16 , which observed changes in pressure on the sacrum and 
 buttock according to different angles of inclination of a tilt table , also indicated that as 
 the inclination angle continues to increase , body weight is gradually transferred to the 
 lower limbs . our study suggested that use of a tilt table for partial weight bearing can enable accurate 
 loading of a prescribed target body weight and that a tilt table can be used stably and 
 efficiently for orthopedic patients , which necessary for partial weight bearing in early 
 rehabilitation . several limitations could be raised and should be taken into account when 
 interpreting the data . our study only measured the longitudinal pressure of the lower limb 
 according to different angles of inclination during tilt table standing . thus , it is 
 difficult to generalize and directly apply the present study to the clinical field . however , 
 our study has meaningful significance in that it suggests quantitative value for weight 
 bearing of the lower limb according to different angles of inclination on the tilt table . if 
 in - depth studies of these issues are performed in the future , the tilt table could become an 
 efficient tool for partial weight training of orthopedic patients , who needs partial weight 
 bearing during early rehabilitation .
[ purpose ] the purpose of this study was to investigate the amount of plantar pressures on 
 the lower limb during tilt table standing and to indicate the ideal degree of tilting for 
 partial weight bearing . 
 [ subjects and methods ] fifteen healthy subjects between the ages 
 of 20 and 30 were recruited as volunteers for this study . 
 all the measurements were taken 
 while standing on a tilt table according to different inclination angles . 
 [ results ] the 
 plantar pressures for 60 tilt table standing were lower by 79% of total body weight than 
 the pressures during tilt table standing at 90 , and the pressures for 30 tilt table 
 standing were lower by 1820% of total body weight than the pressures for tilt table 
 standing at 90. [ conclusion ] standing training on a 60 tilt table might be equivalent to 
 80% of full weight bearing training , and tilt table standing training at 30 might be 
 equivalent to 60% of full weight bearing training .