***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The aim of this study was to evaluate the validity and reliability of volume determinations using the commercially available Seattle ShapeMaker CAD/CAM system for production of prosthetic sockets and to compare it with the commercially available CAPOD system . We used three types of reference objects for volumetric determinations :  steel tubes , plaster of Paris casts , and residual limb models .  Three different sizes were examined for each type of object . Volume measurements with the two CAD/CAM systems were compared with measurements obtained by water filling , water immersion , or mathematical calculation ( tubes only ) . We found an inconsistent systematic error of less than 3.1 % for ShapeMaker and no systematic error for CAPOD .  R and om errors , represented by the coefficient of variation , were below 1.3 % for the ShapeMaker and , in most cases , below 0.4 % for the CAPOD .  Theoretical changes in volume of 2.6 % and 0.8 % are possible to detect with these CAD/CAM systems . In our opinion , both systems have sufficient precision for routine clinical use in prosthetics and orthotics . However , in our study , the ShapeMaker committed larger r and om and systematic errors than CAPOD . This means that , according to our study , CAPOD offers the best possibility to determine and detect small changes in residual limb volume as a function of time The purpose of this study was to evaluate the application of CAD CAM in the production of temporary trans-tibial prostheses . The CAD CAM system was assessed based on the number of socket attempts , number of prosthetic appointments , and temporary prosthesis rehabilitation time . These parameters were considered to be related to the quality of socket fit and were influenced by the entire interdisciplinary team including the patient . A concurrent prospect i ve comparison between the CAD CAM system and an established fibreglass/pelite liner technique was also performed . Patients ( n=30 ) , were fitted with either a conventional or a CAD CAM socket . Records were kept before and after discharge until the interdisciplinary team considered the patient ready for definitive prosthesis casting . After approximately 90 postoperative days , patients were deemed fit to proceed from their initial plaster cast prostheses to their temporary prostheses . The group fitted with conventional sockets had an in-patient rehabilitation phase of 10.5+/−60 days and required 2.9+/−1.1 prosthetic appointments . In- patients fitted with CAD CAM sockets required 5.1+/−1.8 appointments and were hospitalised for 23.6+/−15.0 days . The significantly increased rehabilitation duration and number of appointments ( p=0.01 ) , were generally due to incorrect socket volume and /or inadequately modified relief/loading areas . In this study 67 % of the patients fitted with CAD CAM sockets required at least one additional attempt . The clinical evaluation and modification of the temporary prostheses , including the decision to remake a particular socket , were camed out by the same prosthetist who cast the patients . During the out-patient phase , the type of socket design was not observed to influence either duration of out- patient rehabilitation or frequency of appointments . Out-patient rehabilitation included on average 4 appointments and ended after 90 days . Multidisciplinary discharge criteria and st and ardised follow-up procedures rendered the measured parameters less relevant to this study 's purpose in the out-patient phase This study is an evaluation , from the patient 's point of view , of CAD CAM prosthesis sockets compared with conventional sockets .  Twenty-two trans-tibial amputees were divided into two groups . One group was provided with a CAD CAM ( CAPOD ) socket , the other with a conventionally made one . After one month the groups were evaluated with regard to subjective experience , the judgement of a prosthetist and a physiotherapist , social variables and objective gait parameters . Then the groups switched over to the other type of socket , and after another month a new evaluation was performed . The study design was a single-blind study . In total 175 variables were evaluated . No difference was found between the two types of socket , except for a lower number of terry cloth stockings used in the CAD CAM socket . As the st and ard of conventional prosthetics in Sweden is considered to be high , the results were considered as satisfactory . The quality of the CAD CAM sockets  was at least at the same level as conventionally made ones During the next decade CAD/CAM technique will probably become routine in prosthetics and orthotics , not only as a complement to manual techniques , but also introducing new possibilities . However , even complex and sophisticated techniques have errors of measurement that must be considered . Such errors are of two principal kinds : systematic errors and r and om errors . In this study we have evaluated the Swedish CAPOD system with respect to  volumetric determinations .  We used two types of reference objects for volume determinations :  cylinders and amputation residual limb models .  Three different sizes were examined of each type of object . Volume measurements with CAPOD were compared with  volumes  obtained by water immersion or mathematical calculation ( cylinders only ) . We found a constant , linear systematic error of + 2.5 % . Such an error can easily be corrected for . The r and om error , represented by the coefficient of variation , was 0.5 % , which means that there is a theoretical possibility to detect volume changes exceeding 1 % . We consider the precision sufficient for clinical practice in prosthetics and orthotics . Biological variations due to soft tissue deformation must be added on top of these errors . Such deformations were not evaluated in this study For this r and omized crossover trial , we compared two common transtibial socket suspension systems : the Alpha liner with distal locking pin and the Pe-Lite liner with neoprene suspension sleeve . Our original hypotheses asserted that increased ambulatory activity , wear time , comfort , and satisfaction would be found with the elastomeric suspension system . Thirteen subjects completed the study . Following 2.5-month accommodation to each condition , ambulatory activity was recorded ( steps/minute for 2 weeks ) , and subjects completed three question naires specific to prosthesis use and pain : the Prosthesis Evaluation Question naire ( PEQ ) , a Brief Pain Inventory ( BPI ) excerpt , and the Socket Comfort Score ( SCS ) . Upon completion , subjects selected their favored system for continued use . Ten subjects preferred the Pe-Lite and three the Alpha . Subjects spent 82 % more time wearing the Pe-Lite and took 83 % more steps per day . Ambulatory intensity distribution did not differ between systems . No statistically significant differences were found in question naire results . Subject feedback for each system was both positive and negative In prosthetic practice , the question often arises as to whether the h and cast should be made from a contracted or from a non-contracted amputation stump . To eluci date this question , the authors have performed a study to quantify the volume difference between these 2 conditions , and to relate the differences to prosthetic fitting . Sixteen ( 16 ) trans-tibial amputees participated in the study . All of them were fitted with an ICEROSS silicone socket . Electromyographic  studies , with electrodes attached to the anterior tibial and medial gastrocnemius muscles , were carried out to determine muscle contraction levels . Volume determinations were made with the CAPOD laser scanning system . Measurements were performed with and without the silicone liner on the stump . Without a silicone liner , the volume of the stump increased by 5.8 % ( SD=5.3 ) as the muscles contracted . This increase was statistically significant . With the liner donned the volume increased 3.5 % ( SD=3.3 ) . This increase was also statistically significant . The volume of the prosthetic socket was also compared with the stump volume with a silicone liner on . For the relaxed stump , the difference was 1.8 % ( SD=10.1 ) , and for the contracted stump −1.7 % ( SD=11.3 ) . Neither difference was statistically significant . The importance of these volume changes and how they influence stiffness of the coupling between the stump and the socket are discussed . It is concluded , that the observed difference in volume between a contracted and a non-contracted stump are large enough to be considered by the prosthetist in his decision on how to make a h and cast PURPOSE To perform quantitative evaluation of lower-extremity prosthesis fit by using spiral computed tomography ( CT ) . MATERIAL S AND METHODS Two spiral CT scans were obtained at each of two different sessions in seven adult patients who had undergone amputation below the knee . A rigid-body transformation of the tibia was computed and used to align paired ( intra- and intersession ) spiral CT data sets for each individual in a common coordinate system . Paired scans in each individual were compared to assess registration and precision of soft-tissue change measurement . Clinical prosthesis fit evaluation was demonstrated in an adult amputee volunteer who underwent CT evaluation  while wearing two different prostheses  . RESULTS In the seven patients examined , more than 90 % of the measured soft-tissue volume displacements between sessions could be explained as true differences . Precision error of soft-tissue volume change was approximately 13 cm3 , or approximately 1 % error relative to the mean volume . Volumetric changes due to different prostheses were substantially larger than the r and om error . CONCLUSION Registration of CT volumetric data sets to quantify residual-limb soft-tissue envelope change in lower-limb prosthetics is precise and can be used to detect the effect of prosthesis shape alterations OBJECTIVE To analyze the reliability of 4 methods ( water immersion , computer-aided design [ CAD ] photometric method , CAD h and scanner , and circumferential measurements ) for stump volume measurement in transtibial amputees . DESIGN Repeated measurements . SETTING General community , ambulatory care . PARTICIPANTS Transtibial amputees ( N=26 ; mean age ± SD , 58.7±11.0y ) . INTERVENTIONS Stump volume of patients with an amputation was measured on 2 occasions , each consisting of 2 sessions . In each session , stump volume  was measured by 2 observers using each of the 4 methods . Sequence of observers and measurement methods was determined r and omly . MAIN OUTCOME MEASURE Repeatability coefficients , as a measure for reliability , for each method were calculated , as well as variance components to estimate the influence of measurement conditions on stump volumes measured . RESULTS Repeatability coefficients varied from 129mL CAD h and scanner to 158mL CAD photometric method . Error variance contributed 12 % to the total variance . Methods contributed 36 % , method -amputee and occasion-amputee interactions contributed both 25 % to the error variance . CONCLUSIONS Repeatability coefficient was lowest for the CAD h and scanner , which indicates the best reliability . Substantial differences existed in stump volumes measured between the 4 methods OBJECTIVE The aim was to evaluate stump/socket interface pressure in amputees wearing a socket developed by a pressure casting system .  Design . Five unilateral transtibial amputees wore a pressure cast socket and walked at a self-selected speed . BACKGROUND The socket produces equally distributed pressure at the stump/socket interface , deviating from the conventional belief that pressure varies in proportion to the pain threshold of different tissues in the stump . METHODS The socket was fabricated while the subject placed his stump in a pressure chamber . Pressure was applied while he adopted a normal st and ing position . A specially built strain gauged type pressure transducer was used for measuring pressure distribution . Pressure and gait parameters were measured simultaneously while the subjects were st and ing and walking . RESULTS AND CONCLUSION The pressure cast technique was able to provide comfortable fitting sockets . A hydrostatic pressure profile was not evident during st and ing or gait . Results also showed that no st and ard pressure profile for the pressure cast socket was observed . This was expected as no rectifications were done on the pressure cast socket . Pressure profiles at 10 % , 25 % and 50 % of gait cycle did not correlate with the pressure profiles previously proposed . RELEVANCE The hydrostatic theory is an attractive concept in socket design as it produces a stump/socket pressure profile that is evenly distributed . Furthermore , it is a method that is easily implemented , independent of a prosthetist 's skill and experience and reduces manufacturing time . However , there is still controversy surrounding the efficacy of this hydrostatic theory The current method for fabricating prosthetic sockets is to modify a positive mold to account for the nonhomogeneity of the residual limb to tolerate load ( i.e. , rectified socket ) . We tested unrectified sockets by retaining the shape of the residual limb , except for a distal end pad , using an alginate gel process instead of casting . This investigation compared rectified and unrectified sockets .  Forty-three adults with unilateral transtibial amputations were tested after r and omly wearing both rectified and unrectified sockets for at least 4 weeks . Testing included a gait analysis , energy expenditure , and the Prosthesis Evaluation Question naire ( PEQ ) . Results indicated no differences between sockets for gait speed and timing , gait kinematics and kinetics , and gait energy expenditure . There were also no differences in the PEQ , and 16 subjects selected the rectified socket , 25 selected the unrectified socket , and 2 subjects selected to use both sockets as their exit socket . Results seemed to indicate that more than one paradigm exists for shaping prosthetic sockets , and this paradigm may be helpful in underst and ing the mechanisms of socket fit . The alginate gel fabrication method was simpler than the traditional method . The method could be helpful in other countries where prosthetic care is lacking , may be helpful with new amputees , and may be helpful in typical clinics to reduce costs and free the prosthetist to focus more time on patient needs 
    Output:
    
Conclusion : Overall evidence was weak in suggesting that effects on outcomes were due to the sole influences of shape capture .
However , studies suggest that h and s-on methods are dependent on a prosthetist ’s skill .
H and s-off methods , although repeatable , might still require experience to attain a good fit .
The relation between socket fit and comfort is still unclear .
Clinical relevance A good fitting prosthetic socket is crucial for efficient and comfortable use of a prosthesis .