A pelvic kinematic approach for calculating hip angles for active hip disarticulation prosthesis control.

BACKGROUND: Control system design for a microprocessor-controlled hip-knee-ankle-foot (HKAF) prosthesis is a challenge since hip disarticulation amputees lack the entire leg and, therefore, only have pelvis movement as user-guided input. This research proposes a method for determining hip joint angles from pelvis movement in a control system for the next generation of powered prostheses. METHOD: Three-dimensional pelvic motion and stance time of 10 transfemoral (TF) prosthetic users were used to identify important features and to develop an algorithm to calculate hip angles from pelvis movement based on correlation and linear regression results. The algorithm was then applied to a separate (independent) TF group to validate algorithm performance. RESULTS: The proposed algorithm calculated viable hip angles during walking by utilizing pelvic rotation, pelvic tilt, and stance time. Small angular differences were found between the algorithm results and motion capture data. The greatest difference was for hip maximum extension angle (2.5 ± 2.0°). CONCLUSIONS: Since differences between algorithm output and motion data were within participant standard deviations, the developed algorithm could be used to determine the desired hip angle from pelvis movements. This study will aid the future development of gait control systems for new active HKAF prostheses.

Long short-term memory models to quantify long-term evolution of streamflow discharge and groundwater depth in Alabama.

Long short-term memory (LSTM) models have been shown to be efficient for rainfall-runoff modeling, and to a lesser extent, for groundwater depth forecasting. In this study, LSTMs were applied to quantify the spatiotemporal evolution of surface and subsurface hydrographs in Alabama in the Southeastern United States, where water sustainability has not been fully quantified across spatiotemporal scales. First, the surface water LSTM model with extensive dynamic (precipitation and other weather variables) and static (basin characteristics) inputs predicted the main characteristics of streamflow for six years at 19 gauged basins in Alabama. The model tended to underestimate extremely high streamflow but adding drainage density as an input feature slightly improved the predictions of extreme events. Second, to predict the groundwater depth evolution, a groundwater LSTM (GW-LSTM) model was proposed and applied using static inputs capturing the aquifers' hydrogeological properties and dynamic inputs of meteorological information. Three precipitation scenarios were also explored to evaluate the groundwater hydrograph evolution in the next two decades. The GW-LSTM model predicted the general trend of daily groundwater depth fluctuations (at 21 wells distributed across Alabama from 1990 to 2021) including most extremely high groundwater levels, and recovered groundwater depth for locations withheld from model training and validation. This study, therefore, extended the application of LSTMs in quantifying the spatiotemporal evolution of surface water and groundwater, two manifestations of a single integrated resource.

Design and evaluation of a hip prosthesis simulator: A technical note.

People with a limb loss at the level of the hip or pelvis have the most difficulty returning to walking compared with those with a lower amputation. This is because their prosthesis must replace the hip, knee, and ankle joints. An adjustable hip-disarticulation/hemipelvectomy prosthesis simulator that allows able-bodied individuals to wear and assess a prosthesis can help researchers and manufacturers when designing new prosthetic components (ie, hip joints). SolidWorks computer-aided design software was used to design and simulate an adapter that can connect prosthetic components to an off-the-shelf hip abduction orthosis. The adapter was made of 1020 stainless steel and aluminium 6061-T3 with a yield strength of 276 MPa. To confirm that this adapter is strong and safe for ambulation, mechanical testing was performed using an INSTRON machine. The maximum loads generated in any activity were chosen according to the International Organization for Standardization 15032:2000 standard for hip disarticulation external prostheses. The designed adapter allowed frontal, lateral, or distal mounting of different prosthetic hip joints. Mechanical testing confirmed that the new adapter can withstand forces and moments experienced during ambulation. The hip disarticulation/hemipelvectomy prosthesis simulator is easy to use and adjustable based on each person's height and pelvic width. Furthermore, this simulator would assist rehabilitation practitioners in experiencing the use of hip-level prostheses and give them a better understanding of people using such technologies. The next step in this project is to evaluate able-bodied participant gait while using this hip simulator prosthesis with different hip joints.

Cross slope gait biomechanics for individuals with and without a unilateral transtibial amputation.

BACKGROUND: This research was conducted to better understand compensatory strategies during cross-slope walking for adults with and without a unilateral transtibial amputation. METHODS: Fourteen individuals with unilateral transtibial amputation and 14 individuals with no lower limb amputation participated in this study. Motion and force data were captured while participants walked on a treadmill in a virtual reality environment for level and ± 5° cross slopes. Temporal-spatial parameters, kinematics (ankle, knee, hip, pelvis, trunk), and ground reaction forces were examined. FINDINGS: Compared to level, participants had similar step width but slightly longer steps for top-cross-slope and slightly shorter steps for bottom-cross-slope. Top-cross-slope required a more flexed limb with ankle eversion, and bottom-cross-slope required a more extended limb with ankle inversion. Participants had similar lateral pelvis and trunk motion for all walking conditions, but slightly more anterior trunk lean for top cross-slope with more anterior trunk lean observed for individuals with a lower limb amputation than without lower limb amputation. Participants with a lower limb amputation compensated for limited prosthetic ankle-foot dorsiflexion on the top-cross-slope by increasing prosthetic side hip flexion, reducing intact ankle/knee flexion, and increasing intact push-off force. INTERPRETATION: Gait adaptations during cross-slope walking were primarily in the lower extremities and were largely similar for those with and without a transtibial amputation. The information presented in this paper provides a better understanding of gait strategies adopted during cross-slope walking and can guide researchers and industry in prosthetic development.

On the use of virtual reality for individuals with upper limb loss: a systematic scoping review.

INTRODUCTION: Virtual reality has recently become a popular application for rehabilitation and motor control research. This technology has emerged as a valid addition to conventional therapy and promises a successful rehabilitation. This study describes recent research related to the use of virtual reality applications in the rehabilitation of individuals with upper limb loss and to see whether this technology has enough proof of its applicability. EVIDENCE ACQUISITION: Searches were conducted with the Web of Science, Google Scholar, IEEE Xplore, and PubMed databases from inception up to September 2020. Articles that employed virtual reality in the rehabilitation of individual with upper limb loss were included in the research if it is written in English, the keyword exists in the title and abstract; it uses visual feedback in nonimmersive, semi-immersive, or fully immersive virtual environments. Data extraction was carried out by two independent researchers. The study was drafted using the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA). EVIDENCE SYNTHESIS: A total of 38 articles met the inclusion criteria. Most studies were published between 2010 and 2020. Thirty-nine percent of the studies (N.=15), originates from North America; 55% of the studies (N.=21), were publicly funded; 61% of the studies (N.=24), was without disclosure of conflict of interest; 82% of the studies (N.=31), were cited in other studies. All the studies were published in journals and conference proceedings. Sixty-six percent of the studies (N.=25) has come out with positive outcome. The design studies were mostly case reports, case series, and poorly designed cohort studies that made up 55% (N.=21) of all the studies cited here. CONCLUSIONS: The research conducted on the use of virtual reality in individual with upper limb loss rehabilitation is of very low quality. The improvements to the research protocol are much needed. It is not necessary to develop new devices, but rather to assess existing devices with well-conducted randomized controlled trials.

Production performance, egg quality and some blood parameters of heat-stressed laying hens as affected by dietary supplemental Vit B6, Mg and Zn.

OBJECTIVES: The effects of dietary supplements, including magnesium sulfate (Mg), zinc oxide (Zn) and vitamin B6 (Vit B6), on the performance of laying hens reared under normal (NC) and heat-stress (HSC) conditions were investigated. MATERIAL AND METHODS: A total of 288 30-week-old Lohmann LSL-Lite laying hens were randomly divided into 48 cages and assigned to receive one of the eight diets with six replicates and six hens per replicate, based on a 2 × 2 × 2 factorial arrangement of treatments. Dietary supplements, including two levels (0 & 600 mg/kg) of Mg, two levels (0 & 30 mg/kg) of Zn and two levels (0 & 8 mg/kg) of Vit B6, in normal and heat-stress conditions, were tested at 30-40 and 41-45 weeks of age, respectively. RESULTS: In the Vit B6 group, a decrease in feed intake (FI), egg production (EP), albumin, Zn, Fe and Mg, and an increase in triglyceride and insulin in HSC were observed, in addition to a decrease in cholesterol and an increase in egg weight (EW) in NC. Supplemental Mg decreased EP, blood triglycerides and copper in NC, and Zn, Fe and Mg in HSC as well. Feeding Zn, increased egg shape index, total protein and copper in addition to yolk index in NC and Fe in HSC. EWs were higher in hens supplemented with Vit B6+Mg in HSC. Increased insulin and decreased glutathione peroxidase activity were detected with the Vit B6+Zn compared to feeding either Vit B6 or Zn in HSC. CONCLUSIONS: The results indicated Vit B6 could improve EWs and suppress blood cholesterol in NC. Zn improved the egg shape index in NC.

Hip disarticulation and hemipelvectomy prostheses: A review of the literature.

BACKGROUND: Although the global population of people with a hip disarticulation (HD) or hemipelvectomy (HP) amputation is small, the degree of disability is high, affecting function and independence. A comprehensive literature review is needed to examine the evidence for prostheses in these amputation levels. METHOD: A scoping literature review was conducted to examine related research documents from 1950 to September 2020, found using Scopus, Web of Science, PubMed, and Google Scholar databases. Studies evaluated (retrospectively or prospectively) HD or HP prostheses and were written in English. Study design and protocol, research instrument, sample size, and outcome measures were reviewed. RESULTS: In the past 70 years, 53 articles that evaluated HD or HP prostheses were published. Most research was conducted in the United States (24 articles) and Japan (nine articles). In 42 articles, authors prospectively evaluated the effects of prostheses in these amputation levels. On average, prospective studies had four (SD = 5) participants. Since 1950, only five prospective studies evaluated HD or HP prostheses with 10 or more participants. Moreover, sufficient information was often unavailable for research replication. CONCLUSION: More evidence is needed regarding the effects of HD or HP prosthetic components (i.e. hip, knee, ankle, socket type, and suspension system) on gait, patient satisfaction, prosthetic use, interface pressure, and energy expenditure. Articles mostly have small sample sizes that reduce confidence in the reliability of their findings and limit generalizability. Future investigations are needed with vigorous methodology and larger sample sizes to provide strong statistical conclusions.

A review of history of CAD/CAM system application in the production of transtibial prosthetic socket in developing countries (from 1980 to 2019).

The development of the CAD/CAM (Computer-aided design and computer-aided manufacturing) system has globally changed the fabrication and delivery of prosthetics and orthotics. Furthermore, since the introduction of CAD/CAM in the 1980s, many successful CAD/CAM system are available in the market today. However, less than 20% of amputees have access to digital fabrication technology and large portion of the amputees are from the developing countries. This review designed to examine selected studies from 1980 to 2019 on CAD/CAM systems in the production of transtibial prosthetic sockets. A review was conducted based on articles gathered from Web of Science, Pubmed and Science Direct. From the findings, 92 articles found related to CAD/CAM-derived transtibial prosthetic socket (TPS). After a further screening of the articles, 20 studies were chosen and only one study was done in a developing country. The results showed an increase interest in CAD/CAM application in Transtibial prosthetic socket (TPS) production for both developed and developing countries, yet the technology has not fully utilised in the developing countries. Factors such as resources, accessibility, knowledge-gap and lack of experienced prosthetists remain the major causes of the lack of CAD/CAM system studies. Large-scale trials are required to employ digital fabrication in the developing regions, consequently advancing the production of high-quality CAD-CAM-derived TPS where most prosthetic and orthotics are needed.

Compression and tension behavior of the prosthetic foam materials polyurethane, EVA, Pelite™ and a combination of polyurethane and EVA: a preliminary study.

Materials with low-strength and low-impedance properties, such as elastomers and polymeric foams are major contributors to prosthetic liner design. Polyethylene-Light (Pelite™) is a foam liner that is the most frequently used in prosthetics but it does not cater to all amputees' limb and skin conditions. The study aims to investigate the newly modified Foam Liner, a combination of two different types of foams (EVA + PU + EVA) as the newly modified Foam Liner in terms of compressive and tensile properties in comparison to Pelite™, polyurethane (PU) foam, and ethylene-vinyl acetate (EVA) foam. Universal testing machine (AGS-X, Shimadzu, Kyoto, Japan) has been used to measure the tensile and compressive stress. Pelite™ had the highest compressive stress at 566.63 kPa and tensile stress at 1145 kPa. Foam Liner fell between EVA and Pelite™ with 551.83 kPa at compression and 715.40 kPa at tension. PU foam had the lowest compressive stress at 2.80 kPa and tensile stress at 33.93 kPa. Foam Liner has intermediate compressive elasticity but has high tensile elasticity compared to EVA and Pelite™. Pelite™ remains the highest in compressive and tensile stiffness. Although it is good for amputees with bony prominence, constant pressure might result in skin breakdown or ulcer. Foam Liner would be the best for amputees with soft tissues on the residual limbs to accommodate movement.

The effect of various arm and walking conditions on postural dynamic stability when recovering from a trip perturbation.

BACKGROUND: Appropriately responding to unexpected perturbations, such as a trip, is critical to sustain balance and avoid falling during walking. RESEARCH QUESTION: How do arm motion and walking asymmetry affect postural stability when recovering from a trip perturbation? METHODS: Fifteen healthy young individuals, who had no experience with treadmill induced perturbations, participated in this study. The Computer-Assisted Rehabilitation Environment system (CAREN-Extended) was used to simulate unexpected perturbations while walking symmetrically and asymmetrically with various arm swings (normal, bound, released). Whole-body angular momentum (WBAM), peak trunk angular velocities, Center of Mass (COM), step width and stance time were analyzed before and when recovering from trip perturbations. RESULTS: Participants were able to recover their postural stability within three strides following the sudden anterior-posterior trip perturbation. The perturbation increased peak trunk angular velocity, the COM excursion and WBAM but did not affect stance time and step width. The arm conditions had significant effects on peak trunk angular velocity, WBAM and step width during pre-perturbation. Walking conditions had a significant effect on all variables during pre-perturbation; however, post-perturbation showed significant effects only for peak trunk angular velocity, WBAM, and COM. SIGNIFICANCE: Unexpected perturbation had effects on most of gait variables; nevertheless, participants fully recovered and adapted their gait pattern to sudden perturbations even without using their arms while walking symmetrically and asymmetrically. Arm movements could help young individuals recover after a perturbation but are not essential for perturbations of moderate magnitude. The effect of medial-lateral perturbations on gait still need to be investigated.

Effect of arm motion on postural stability when recovering from a slip perturbation.

The aim of this study was to examine the effects of various arm swing on postural stability and recovery responses to an unexpected slip during treadmill walking. Fifteen healthy young adults (23.4 ±â€¯2.8 years old) participated in this study. The CAREN-Extended system was used to simulate unexpected slip perturbations in a safe environment while walking symmetrically and asymmetrically with various arm swings (normal, bound, released). Whole-body angular momentum (range), peak trunk angular velocities, step width and stance time were extracted before and after perturbations (when recovering from slip). All participants were able to recover their balance after two strides and no falls occurred. There were significant differences (p < 0.05) in most gait parameters between pre- and post-perturbations. Arm conditions had significant effects on all gait parameters during both pre- and post-perturbation except for stance time. Compared to symmetric walking, walking asymmetrically before a perturbation led to larger step width and stance time among the different arm conditions both before and after the perturbations. Despite the presence of significant effects of different arm and walking conditions on most gait parameters during pre- and post-perturbation, participants were able to implement stabilization strategies to prevent fall even when they were prevented from using their normal arm swing, in both symmetric and asymmetric walking. While our results indicate that perturbations were mild to moderate in magnitude, investigations with elderly and faller populations are needed to examine their susceptibility to these arm and walking conditions when trying to regain postural balance.

Transtibial amputee gait during slope walking with the unity suspension system.

BACKGROUND: People with lower limb amputation may experience walking limitations on slopes because of missing musculoskeletal and neuromuscular systems. Elevated vacuum suspension could benefit transtibial amputee gait for slope walking, but research is lacking to inform clinical practice. METHODS: Twelve people with unilateral transtibial amputation were fitted with the Unity elevated vacuum suspension system (Össur) and Pro-Flex XC foot. 3D motion analysis was performed for 7° incline, 7° decline, and level walking within a CAREN-Extended system virtual Park environment. Randomized and blinded walking trials were completed with the vacuum active or inactive. RESULTS: Statistically significant differences (p < 0.05) were found between vacuum conditions when walking uphill or downhill for temporal spatial, kinematic, and kinetic gait parameters; however, effect sizes were small (r≤0.35). Prosthetic step length decreased for both vacuum conditions on downhill compared to uphill walking. Symmetry index was <10% for step length, step time, and stance time for both vacuum condition during downhill walking, indicating acceptable symmetry. During incline walking, step length was only symmetrical with active vacuum. Knee range of motion was not restricted, for both conditions. CONCLUSION: Active vacuum improved gait symmetry for incline walking, but the other differences between vacuum conditions were small and may not be clinically significant. Therefore, the Unity system approach for elevated vacuum suspension had a positive, but small, effect on walking and should maintain appropriate walking even with vacuum failure, until limb volume changes adversely affect socket fit (i.e., elevated vacuum helps control limb volume fluctuations over time).

Effects of the unity vacuum suspension system on transtibial gait for simulated non-level surfaces.

Walking on various surfaces encountered in everyday life requires lower limb prosthesis users to continually adapt their movement patterns. Elevated vacuum suspension systems could improve transtibial amputee gait on non-level surfaces; however, research is lacking to guide clinical practice. Twelve transtibial amputees were fitted with the Össur sleeveless vacuum suspension system (Unity). After a one month accommodation period, the CAREN-Extended system was used to evaluate gait on a self-paced treadmill when walking with continuous perturbations (medial-lateral translations, rolling hills, simulated uneven ground) with an active or inactive vacuum suspension system. Significant differences between active and inactive vacuum conditions (p<0.05) were found for some temporal-spatial and kinematic gait parameters, but the differences were small and not considered clinically significant. Our findings suggest that potential vacuum pump failures would not immediately affect gait performance in a moderately high functioning amputee population. However, residual limb volume changes over time due to the removal of elevated vacuum may adversely affect socket fit, leading to greater gait differences and reduced quality of life.

Awareness, potential factors, and post-amputation care of stump flexion contractures among transtibial amputees.

OBJECTIVES: This study aims to assess the level of awareness of transtibial amputee patients on stump contractures and their compliance with efforts implemented to prevent the condition. PATIENTS AND METHODS: This study included 50 unilateral transtibial amputees (26 males, 24 females; mean age 55.4±14.7 years; range, 18 to 78 years) who met the respondent criteria of the study. The respondents were randomly selected and were issued with a questionnaire. RESULTS: The majority of the transtibial amputees were aware of stump contracture complications. It was found that they also preferred methods of prevention which required less effort, was cost-effective, and were also practical. CONCLUSION: More focus should be placed on contracture prevention methods which were most complied with by the patients. This is because the effectiveness of a prevention method is highly influenced by patients' compliance with the method. Patients with a higher risk of developing stump contractures should be also given more attention in post-amputation care.

Improvement on upper limb body-powered prostheses (1921-2016): A systematic review.

Body-powered prostheses are known for their advantages of cost, reliability, training period, maintenance, and proprioceptive feedback. This study primarily aims to analyze the work related to the improvement of upper limb body-powered prostheses prior to 2016. A systematic review conducted via the search of the Web of Science electronic database, Google Scholar, and Google Patents identified 155 papers from 1921 to 2016. Sackett's initial rules of evidence were used to determine the levels of evidence, and only papers categorized in the design and development category and patents were analyzed. A total of 40 papers in the sixth level of "Design and Development" of an upper limb body-powered prosthesis were found. Approximately 81% were categorized under mechanical alteration. Most papers were patent-type documents (48%), with the Journal of Rehabilitation Research and Development publishing most of the articles related to the design and development of body-powered prostheses. Papers in the scope of the study were published once every 3 years in almost a century, proving that only a few studies were conducted to improve body-powered arms compared with myoelectric technology. Further research should be carried out mainly in areas that have received less attention.

Clinical evaluation of a prosthetic suspension system: Looped silicone liner.

OBJECTIVES: This study aimed to evaluate and compare a newly designed suspension system with a common suspension in the market. STUDY DESIGN: Prospective study. METHODS: Looped liners with hook fastener and Iceross Dermo Liner with pin/lock system were mechanically tested using a tensile testing machine in terms of system safety. A total of 10 transtibial amputees participated in this study and were asked to use these two different suspension systems. The pistoning was measured between the liner and socket through a photographic method. Three static axial loading conditions were implemented, namely, 30, 60, and 90 N. Furthermore, subjective feedback was obtained. RESULTS: Tensile test results showed that both systems could safely tolerate the load applied to the prosthesis during ambulation. Clinical evaluation confirmed extremely low pistoning in both systems (i.e. less than 0.4 cm after adding 90 N traction load to the prosthesis). Subjective feedback also showed satisfaction with both systems. However, less traction at the end of the residual limb was reported while looped liner was used. CONCLUSION: The looped liner with hook fastener is safe and a good alternative for individuals with transtibial amputation as this system could solve some problems with the current systems. Clinical relevance The looped liner and hook fastener were shown to be good alternative suspension for people with lower limb amputation especially those who have difficulty to use and align the pin/lock systems. This system could safely tolerate centrifugal forces applied to the prosthesis during normal and fast walking.

Prosthesis donning and doffing questionnaire: Development and validation.

OBJECTIVES: To develop a questionnaire that specifically evaluates the ability of trans-tibial amputees to don and doff a prosthesis and to investigate the psychometric properties of the newly developed questionnaire. BACKGROUND: Prosthesis should be donned and doffed few times during the day and night; thus, it is important to measure ease of donning and doffing. STUDY DESIGN: A cross-sectional study. METHODS: The questionnaire was designed and evaluated by a group of experts. The final questionnaire was administered to 50 individuals with trans-tibial amputation. A test-retest study was also conducted on 20 amputees to assess the repeatability of questionnaire items. RESULTS: The prosthesis donning and doffing questionnaire was developed and tested through a pilot study. Based on Kappa index, the questionnaire items showed correlation coefficients greater than 0.7, which indicate good reliability and repeatability. The majority of the participants had good hand dexterity (80%) and could perform all types of grasps. The mean satisfaction scores with donning and doffing were 69.9 and 81.4, respectively. Most of the respondents needed to don and doff the prosthesis 3.44 times per day. Based on a 7-point score, the total scores ranged between 3 and 7. CONCLUSION: The prosthesis donning and doffing questionnaire items showed good psychometric properties. A scoring method was suggested based on the pilot sample, which requires further evaluation to be able to differentiate between more suspension types. A larger international multicenter evaluation is required in the future to measure the responsiveness of the scales. This questionnaire will be useful in the evaluation of the ability of amputees to don and doff a trans-tibial limb prosthesis. Clinical relevance Donning and doffing of prostheses are challenging tasks for many lower limb amputees. The prosthesis donning and doffing questionnaire, on its own or combined with other prosthetic evaluation questionnaires, has the potential to help manufacturers, clinicians, and researchers gain knowledge and improve the donning and doffing qualities of prostheses.

Analysis of voluntary opening Ottobock Hook and Hosmer Hook for upper limb prosthetics: a preliminary study.

There are a number of prosthetic terminal devices which offer functional restoration to individuals with upper limb deficiencies. Hosmer and Ottobock are major commercial hook providers for prosthetic terminal devices. The concern of this paper is to analyse the voluntary opening (VO) Ottobock model 10A18 and Hosmer model 99P hooks (one band) during opening operation and to find out favourable features in the design. Two tests were conducted to analyse the performance of both hooks. The first test used a simple bench tool to investigate cable excursion and hook opening angle and the second test used force sensor to find out the force supplied at a different hook opening angle. The study found that the average cable excursion for both hooks is approximately 30% less than the hook's opening span with the force at the hook's tip section being inversely proportional to the force at the lateral section. Ottobock 10A18 has a better control for grasping larger objects, while Hosmer 99P has the highest average force at the tip section but yet less efficient in generating adequate force for activities of daily living. Favourable features identified are low cable excursion per hook opening span and balance lateral to hook tip pinch force.

WITHDRAWN: Patient-specific interface pressure case study at transradial prosthetic socket: comparison trials between ICRC polypropylene socket and air splint socket.

Ahead of Print article withdrawn by publisher

A comparison of pressure distributions between two types of sockets in a bulbous stump.

BACKGROUND: This article describes a total surface bearing prosthetic socket for a patient (25-year-old female) with a bulbous stump. CASE DESCRIPTION AND METHODS: The subject had unstable excessive soft tissue at the distal end of the residuum. After 2 years of prosthetic use, she experienced several problems, including pain in the residual limb and knee joint. Pressure distribution was evaluated during ambulation. We also designed a total surface bearing socket with Velcro as suspension system to distribute the load evenly on the residual limb, and to facilitate donning procedure. FINDINGS AND OUTCOMES: The main site of weight bearing in the old prosthesis (patellar tendon bearing) was anterior proximal region of the residual limb, especially the patellar tendon. The pressure was almost 10 times higher than the distal region during level walking. Pressures were distributed more evenly with the total surface bearing socket design, and the donning was much easier. CONCLUSION: Pressure distribution within the socket could be affected by socket design and suspension system. Using the total surface bearing socket and Velcro as suspension system might facilitate donning of prosthesis and reduce traction at the end of residual limb during the swing phase of gait. CLINICAL RELEVANCE: Proper socket design and suspension system based on the amputees' need can facilitate rehabilitation process and lead to the amputee's satisfaction. The pressure is distributed more uniformly over the residual limb by the total surface bearing socket compared to the patellar tendon bearing socket for lower limb amputees with unusual stump shape.