This study relates the gait asymmetry, residual limb comfort, and energy cost during walking and identifies a compensating pattern for the trans-tibial amputees when the prostheses are misaligned. One male subject wit...This study relates the gait asymmetry, residual limb comfort, and energy cost during walking and identifies a compensating pattern for the trans-tibial amputees when the prostheses are misaligned. One male subject with a trans-tibial amputation volunteered for the study. The knee joint moments at the prosthetic side, the phase symmetry index, and the interface pressures were discussed under three sagittal alignment settings. The results show that the subject changes the knee joint moment, gait symmetry, and interface pressure with a misaligned prosthesis to improve his comfort and movement during walking. A high-quality liner reduces the gait sensitivity to misalignment and enhances the amputee＇s ability to compensate for misalignment. Since different people have different compensation patterns, more cases will be studied in future work.展开更多
Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventi...Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA.Methods：We conducted a retrospective analysis of 212 primary TKAs in 188 patients.Intramedullary （IM）-guided resection was applied on the femoral side while extramedullary （EM）-guided resection was used on the tibial side.Using full-length X-ray,the preoperative femoral valgus angle and lower extremity alignment,as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment,were measured.Results：Postoperatively,good prosthetic alignment was achieved in 191 cases （90.1%） on the tibial side and in 144 cases （67.9%） on the femoral side （χ^2 =5.441,P =0.02）.Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane.Data were divided into five subgroups based on the valgus or varus status of the prostheses.The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414,respectively;in varus on both sides were 0.658 and 0.377,respectively;in valgus,0.555 and 0.030;femoral side varus and tibial side valgus,0.702 and 0.211;femoral side valgus and tibial side varus,-0.416 and 0.287.The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment,except for the tibial prosthetic alignment when femoral prosthesis was in valgus （P =0.153）.Conclusions：In conventional TKA,tibial side EM-guided resection may offer satisfactory postoperative alignment,and femoral resection relying on IM guide may lead to more undesirable results.Postoperative coronal alignment is mainly affected by the femoral resection.Therefore,femoral side operation should receive adequate attention from the surgeons.展开更多
This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation voluntee...This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography （EMG） of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak pressure was increased in the medial forefoot region, and the peak pressure was reduced in the heel region. The EMG of the medial and lateral gastrocnemius of the sound leg almost doubled and that of the rectus fomris, vastus lateralis, and vastus medialis of the prosthetic side increased to different extents with in- creasing heel heights from zero to 40 mm. These results show a high correlation with human physical be- havior. Changing of the heel heights for trans-tibial amputees during standing actually had similar effects to altering the prosthetic sagittal alignment. The results suggest that an alignment change is necessary to accommodate heel height changes and that prosthesis users should be cautious when choosing shoes.展开更多
基金the National Natural Science Foundation of China (No. 50305013)
文摘This study relates the gait asymmetry, residual limb comfort, and energy cost during walking and identifies a compensating pattern for the trans-tibial amputees when the prostheses are misaligned. One male subject with a trans-tibial amputation volunteered for the study. The knee joint moments at the prosthetic side, the phase symmetry index, and the interface pressures were discussed under three sagittal alignment settings. The results show that the subject changes the knee joint moment, gait symmetry, and interface pressure with a misaligned prosthesis to improve his comfort and movement during walking. A high-quality liner reduces the gait sensitivity to misalignment and enhances the amputee＇s ability to compensate for misalignment. Since different people have different compensation patterns, more cases will be studied in future work.
文摘Background：A good postoperative alignment in total knee arthroplasty （TKA） is the key to achieving satisfactory results.We assessed the effect of femoral and tibial resection on the overall alignment after conventional TKA.Methods：We conducted a retrospective analysis of 212 primary TKAs in 188 patients.Intramedullary （IM）-guided resection was applied on the femoral side while extramedullary （EM）-guided resection was used on the tibial side.Using full-length X-ray,the preoperative femoral valgus angle and lower extremity alignment,as well as 2-week postoperative femoral and tibial prosthetic coronal alignment and overall lower extremity alignment,were measured.Results：Postoperatively,good prosthetic alignment was achieved in 191 cases （90.1%） on the tibial side and in 144 cases （67.9%） on the femoral side （χ^2 =5.441,P =0.02）.Multiple linear regression analysis was used to assess the effect of different alignment sides on the overall alignment in the coronal plane.Data were divided into five subgroups based on the valgus or varus status of the prostheses.The standardized regression coefficients of the femoral and tibial prosthetic alignment on the overall alignment were 0.666 and 0.414,respectively;in varus on both sides were 0.658 and 0.377,respectively;in valgus,0.555 and 0.030;femoral side varus and tibial side valgus,0.702 and 0.211;femoral side valgus and tibial side varus,-0.416 and 0.287.The study showed that the overall low extremity alignment was statistically influenced by the prosthetic alignment,except for the tibial prosthetic alignment when femoral prosthesis was in valgus （P =0.153）.Conclusions：In conventional TKA,tibial side EM-guided resection may offer satisfactory postoperative alignment,and femoral resection relying on IM guide may lead to more undesirable results.Postoperative coronal alignment is mainly affected by the femoral resection.Therefore,femoral side operation should receive adequate attention from the surgeons.
基金Supported by the National Natural Science Foundation of China(No. 50575122)
文摘This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography （EMG） of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak pressure was increased in the medial forefoot region, and the peak pressure was reduced in the heel region. The EMG of the medial and lateral gastrocnemius of the sound leg almost doubled and that of the rectus fomris, vastus lateralis, and vastus medialis of the prosthetic side increased to different extents with in- creasing heel heights from zero to 40 mm. These results show a high correlation with human physical be- havior. Changing of the heel heights for trans-tibial amputees during standing actually had similar effects to altering the prosthetic sagittal alignment. The results suggest that an alignment change is necessary to accommodate heel height changes and that prosthesis users should be cautious when choosing shoes.
