Dynamic stability evaluation of trunk accelerations during walking in blind and sighted individuals.

BACKGROUND: Dynamic stability is a fundamental goal in standing activities. In this regard, monitoring, analysis, and interventions made to improve stability is a research topic investigated in the biomechanics of human movements. Vision has a major role to play in controlling human movement. Nonetheless, little is known about the effects of visual deprivation, especially from birth on dynamic gait stability. METHODS: The current study was conducted on 20 congenital blind and 10 sighted people (15-38 years). To evaluate the dynamic stability, descriptive data, harmonic ratio (HR), improved harmonic ratio (iHR), and root mean square (RMS), based on trunk acceleration data were measured in three axes: anteroposterior (AP), vertical (V), and mediolateral (ML) while participants walked an eight-meter straight path. RESULTS: In the comparison of blind and sighted people (eyes open), standard deviation, HR, iHR, and RMS indices were found to be significantly different in both AP and V directions. All the mentioned parameters were significantly lower in blind than in sighted participants. In the comparison of blind people and sighted ones with closed eyes, changes were observed in the maximum, range, standard deviation, and RMS only in the AP axis. In the comparison between eyes open and closed in sighted people, a significant difference was found only in the harmonic ratio of the vertical axis. CONCLUSION: Visual deprivation led to a decrease in dynamic stability parameters in the AP and V axes. Even the movement of sighted people in unchallenged conditions is dependent on visual information.

Evaluation of Mandibular Movements in Patients with Bell's Palsy Using Kinematic Variables.

Background: Since the function of muscles, and subsequently the mandibular joint, is affected in patients with Bell's palsy, therefore, the evaluation of facial muscles and mandibular function in these patients can be effective in diagnosis, prevention, and treatment planning. The present study aimed to evaluate the degree of displacement and range of motion (ROM) of the mandible and the ability of the facial symmetrical muscles of patients with Bell's palsy. Methods: This was a quasi-experimental comparative study. The variables evaluated were mandibular movement in a vertical direction and side-to-side displacement. Ten patients with Bell's palsy and 10 healthy eligible volunteers participated in the present study. Three mobile video cameras (to record jaw movements), 9 color markers, Kinovea software, House-Brackmann index, Toledo protocol, and a specialized patient questionnaire were used. Descriptive and inferential statistics were used for data analysis, the Kolmogorov-Smirnov test was used to investigate the normality of data distribution, and independent samples the t test and paired samples t test were used to compare means. Results: The maximum lateral on the sound side was 12.40 and 4.49 mm during lateral movements of the patients' mandible, while this value was between 12.30 and 3 mm on the involved side. There is a difference between the affected side and the nonaffected side in terms of the mean lateral movements of the patients' mandible. However, this difference in the mean ROM on both sides is not statistically significant. The maximum mouth opening in healthy individuals during mandibular movements was between 40 and 60 mm, while this value was between 25 and 50 mm in the patients with Bell's palsy. This study shows a significant difference (P = 0.007) between patients and healthy individuals in terms of the mean of maximum mouth opening ( P < 0.05). Conclusion: The results of this study showed that the ROM of temporomandibular joint (TMJ) of the patient is the same as that of normal subjects, but the side-to-side motion is more than normal which should be considered in rehabilitation treatments. The present study emphasizes the need to implement a mandibular kinematic evaluation protocol in patients with bell's palsy to prevent damage to the TMJ in the long term.

The Effects of Lower Limb Orthoses on Health Aspects of the Spinal Cord Injury Patients: A Systematic Review Using International Classification of Functioning, Disability, and Health (ICF) as a Reference Framework.

Background: One of the most important approaches in the rehabilitation of spinal cord injury (SCI) patients is the use of different orthoses. To date, no review has been published that analyzed the effects of orthoses on health aspects of spinal cord injury clients using the International Classification of Functioning, Disability and Health (ICF). Methods: A systematic literature search was done in some databases, including Medline, PubMed, Cochrane centered register of the controlled trial (CCTR), Cochrane database of systematic reviews (CDSR), a database of abstracts of reviews of effects (DARE), Embase, Google Scholar, and ISI Web of Knowledge. SCI was used in conjunction with terms like orthotic device, mechanical orthoses, external power orthoses, assistive devices, and functional electrical. The time frame for this search was from 1970 to 2022. Results: A total of 200 papers were found. Based on the titles and abstracts, 100 related papers were detected. After careful evaluation of the papers, 47 studies were selected for final analysis-53 papers were excluded due to duplication, non-English language, and lack of full-text. Conclusion: The results of 32 studies (70% of studies) support the efficiency of orthoses in walking and standing of SCI patients. In most of the included studies, the efficiency of orthoses was evaluated mostly based on body functions and structures, and their impact on other outcomes such as participation and quality of life (QoL) of SCI patients was unclear.

Kinematics of the Lumbar Spine and Hip Joints in People with Persistent Low Back Pain during Sit to Stand and Stand to Sit Activities.

Background: To our knowledge, no study has examined the kinematics of lumbopelvic-hip complex of individuals with chronic low back pain (CLBP) who had lumbar flexion+rotation (F+R) syndrome during sit to stand (SiToSt) and stand to sit (StToSi) activities. Thus, this study aimed to examine movement patterns of the lumbopelvic-hip complex in participants with CLBP classified into F+R syndrome subgroup. Methods: This was a cross sectional study. A 3-dimensional motion capture system was used to record movements of the lumbar spine and hips during SiToSt and StToSi. Participants were 20 patients with LBP classified in lumbar F+R subgroup, based on the movement impairment system model, and 20 asymptomatic individuals. The study was approved by Shahid Beheshti University of Medical Sciences (IR, SBMU.RETECH, and REC.1395.365). Results: Greater and significant lumbar flexion, with SiToSt, and lumbar extension, with StToSi, were observed in the patients. In addition, the patients exhibited a greater magnitude of lumbar rotation during SiToSt. No significant difference was observed between the 2 groups in hip motions. Conclusion: The patients with lumbar F+R syndrome tend to move their lumbopelvic region to a greater extent in sagittal and horizontal planes during SiToSt and StToSi compared with participants without low back pain.

An Evaluation of the Effect of Vision on Standing Stability in the Early Stage of Parkinson's Disease.

BACKGROUND: Postural instability is a common disorder in Parkinson's disease (PD). The aim of this study was to evaluate stance stability of the subjects at the early stage of PD with both linear and nonlinear approaches. Moreover, this study aimed to find the effect of visual control on quiet stance postural control in these patients. METHOD: Seventeen PD patients (Hoehn/Yahr scale: 1) and 17 healthy control subjects were instructed to maintain quiet postural stance in 2 conditions (opened eyes and closed eyes). Four linear (excursion, path length, velocity, root mean square) and 1 nonlinear (approximate entropy) center of pressure (COP) parameters were calculated. A 2 × 2 mixed ANOVA was used for the final analysis. RESULTS: Although there was no difference between the stability of PD patients and healthy control subjects based on excursion of COP in both mediolateral (ML) and anteroposterior (AP) directions, other linear parameters (path length of COP sways, velocity of COP sways, and root mean square in both ML and AP planes) showed that PD patients were significantly unstable compared to normal subjects (p value < 0.05). Vision influenced the stability of both groups significantly. The interaction of vision and group was not significant based on linear and nonlinear stability parameters. CONCLUSION: Although patients in the early stage of PD seem to be unstable based on COP linear measures, their postural control system is still flexible to adapt to environmental perturbations in quiet stance and they are not more visually dependent than healthy subjects to control stability in this position.

Resistance exercise training restores bone mineral density in renal transplant recipients.

BACKGROUND: The kidneys are complex organs of human body sustain a number of vital and important functions. These organs need to be replaced in some subjects due to various diseases. Bone mineral density (BMD) of the subjects with kidney transplantation reduced as a result of poor mobility and use of especial drugs. Due to lack of information regarding the influences of weight training exercise on BMD of long bone, this research was done. METHOD: 24 subjects with history of kidney transplantation were recruited in this study. They were divided into two groups who received weight training exercise and control group. The BMD of femur and lumbar spine was measured by use of dual energy X-Ray absorptiometry in both groups. The difference between BMD was evaluated by use of two sample T test. RESULT: The mean values of BMD of femur were 0.679±0.09 g/cm2 and 0.689±0.09 before and after exercise in this first group. In contrast it was 0.643±0.11 before follow-up and 0.641±0.11 g/cm2 after follow-up in the control group. There was no difference in BMD of lumbar spine after exercise. CONCLUSION: The result of this research study showed that BMD of long bone improved follow exercise. Therefore, it was concluded that weight training exercise can be used for the subjects with kidney transplantation.

The effect of a powered ankle foot orthosis on walking in a stroke subject: a case study.

[Purpose] Standing and walking are impaired in stroke patients. Therefore, assisted devices are required to restore their walking abilities. The ankle foot orthosis with an external powered source is a new type of orthosis. The aim of this study was to evaluate the performance of a powered ankle foot orthosis compared with unpowered orthoses in a stroke patient. [Subjects and Methods] A single stroke subject participated in this study. The subject was fitted with three types of ankle foot orthosis (powered, posterior leg spring, and carbon ankle foot orthoses). He was asked to walk with and without the three types of orthoses, and kinetic and kinematic parameters were measured. [Results] The results of the study showed that the moments applied on the ankle, knee, and hip joints increased while walking with the powered ankle foot orthosis. [Conclusion] As the powered ankle foot orthosis influences the moments of the ankle, knee, and hip joints, it can increase the standing and walking abilities of stroke patients more than other available orthoses. Therefore, it is recommended to be used in rehabilitation programs for stroke patients.

Evaluation of the bone mineral density of the subjects with avascular necrosis of hip joint.

BACKGROUND: The head of femur is deformed in subjects with Leg Calve Perthes Disease (LCPD). It may be due to an increase in loads applied on the hip, decrease in hip joint containment and decrease in bone mineral density (BMD) of femur. Unfortunately there is not enough evidence regarding BMD of femur in subjects with LCPD. Therefore, the aim of this study is to evaluate BMD in subjects with Perthes disease. METHOD: Two subjects with LCPD participated in this study. The BMD and Young modulus of elasticity (E) of different parts of femur of both Perthes and sound sides were evaluated by use of Mimics software. The difference between BMD of femur in both sides of each subject was compared by use of two sample t test. RESULTS: There was no difference between the BMD and E modulus of femur in Perthes and sound sides in both subjects (p-value>0.05). CONCLUSION: As there is no difference between the BMD of femur in Perthes side, it can be concluded that the deformation of femur in these subjects may not be due to a change in BMD.

The comparison between various methods of mandibular reconstruction based on finite element analysis.

The Mandible can be damaged by pathological factors, tumors, trauma, infection, and needs a surgical operation for reconstruction and restoring function. There are different methods for the reconstruction of mandible. Based on the surgical approach, primary reconstruction of mandible by reconstruction plate after resection is necessary for maintaining mandibular symmetric and esthetic of the lower third of the face. A finite element model of mandible and masticatory muscles was produced from a normal person (male with 35-year-old). The normal model was resected from the left sixth tooth to the second tooth. The pathological model was reconstructed in different conditions by macro plate. Different conditions were analyzed and compared based on bite force on right fifth tooth, stress developed on screws and macro plate. The finite element analysis results showed that maximum bite force and lower stress on screws were seen in the pathological model (condition 5) when one macro plate and six screws were inserted in the mid-body. The findings showed that the use of two macro plates causes lower stress on it than when we use one. Use of one macro plate and six screws is the best choice in mandibular immobilization which decrease the stress applied on bone and increase the bite force. Because of less stress developed on macro plates and screws, use of two macro plates or one macro plate in mid-body area are also preferred.

Respiratory Function Assessment through Kinematic Analysis of Chest Wall Movements: Effects of Position and Gender.

Background: The effect of position and gender on chest movements and respiratory volumes is controversial and investigated in only a few studies. Objective: This study aimed to investigate the effects of position and gender on the breathing pattern during four different positions in healthy individuals. Material and Methods: In this cross-sectional study, twenty-eight (14 males, 14 females) healthy individuals participated aged 20-45 years. The optoelectronic plethysmography (OEP) method was used for the three-dimensional evaluation of chest wall motions and the compartmental analysis of the breathing pattern in supine, sitting, standing, and active straight leg raised (ASLR) positions. Volume changes in different parts of the chest wall were also measured. Results: Position affected total and compartmental respiratory volumes in both genders. Respiratory volumes decreased in the supine position compared to sitting and standing. Total and abdominal respiratory volumes also decreased in females when comparing supine positions with the ASLR. A higher pulmonary rib cage contribution was identified in females, and males exhibited higher abdominal rib cage volume compared with females. Conclusion: The breathing pattern was affected by position and gender, and the respiratory volumes increased in more upright positions, perhaps due to a greater gravitational load. The ASLR decreases the respiratory volume, which is probably due to increased postural demand.

Investigation of joint contact forces during walking in the subjects with toe in gait due to increasing in femoral head anteversion angle.

Toe-in gait is a pathology in which the child walks and turns the foot inward instead of pointing straight ahead. The alignment of the lower limb structure changes in this disease, increasing the incidence of knee and hip osteoarthritis. This study aimed to determine the kinematic and joint loading in subjects walking with a toe-in gait pattern. This study selected two groups of subjects: normal subjects and those with toe-in gait due to an increased femoral head anteversion angle (each group consisted of 15 subjects). A Qualisys motion analysis system and a Kistler force plate were used to record the motions and forces applied to the leg while walking. OpenSim software (version 3.3) was used to analyze the range of motion, moments, muscle forces, and joint contact forces in both groups of subjects. The mean values of stride length for normal subjects (1.1 ± 0.141 m) and those with toe-in gait (0.94 ± 0.183 m) differed significantly. The mediolateral component of the ground reaction force decreased significantly in the toe-in gait group compared to normal subjects (p-value = 0.05). The peak force of most of the hip joint muscles increased significantly in those with toe-in gait compared to normal subjects (p-value < 0.05). The results of this study showed that those with toe-in gait, due to an increase in femoral head anteversion angle, only had a change in rotation of the pelvic and hip joint. There was no significant difference between walking speed and most ground reaction force components between normal subjects and those with toe-in gait. As the peaks of most of the hip joint muscles increased significantly in the toe-in gait group, this increased joint contact forces (especially the anteroposterior component of the hip joint and the mediolateral component of the knee joint), which may ultimately increase the incidence of hip and knee joint osteoarthritis.

Quantitative EEG for the Monitoring of Walking Recovery in Chronic Stroke Patients Receiving Action Observation Training.

The current study aimed to evaluate the effects of action observation on the walking ability and oscillatory brain activity of chronic stroke patients. Fourteen chronic stroke patients were allocated randomly to the action observation (AO) or sham observation (SO) groups. Both groups received 12 sessions of intervention. Each session composed of 12 min of observational training, which depicted exercises for the experimental group but nature pictures for the sham group and 40 min of occupational therapy, which was the same for the both groups. Walking ability was assessed by a motion analysis system and brain activity was monitored using quantitative electroencephalography (QEEG) before and after the intervention. Brain asymmetry at alpha frequency, the percentage of stance phase, and step length showed significant changes in the AO group. Only the change in global alpha power was significantly correlated with the change in velocity after the intervention in AO group. Despite more improvements in walking and brain activity of patients in the AO group, our study failed to show significant correlations between the brain activity changes and functional improvements after the intervention, which might be mainly due to the small sample size in our study. Trial registration: IRCT20181014041333N1.

Performance of subjects with knee osteoarthritis during walking: differential parameters.

The effect of knee OA on kinetic and kinematic parameters during walking and standing is still controversial. Stability and energy consumption have not been well investigated in patients with OA. This research investigated the parameters distinguishing between the healthy subjects and patients with OA performance. It also examined the differences in stability and energy consumption between patients with OA and healthy subjects. Fifteen patients with OA and fifteen healthy subjects were recruited into this study. Kinematic and kinetic assessments were performed using Qualysis motion analysis and a force plate Kistler, respectively. Stability of the subjects during walking was determined using COP. Energy consumption was calculated using the Physiological Index. Independent t test was used to determine the differences between gait, stability, and energy consumption healthy participants and patients with knee OA. The excursion of the knee, hip and pelvis in sagittal plane, excursion of the knee joint in the mediolateral plane were significantly higher (all p < 0.05) in patients with OA of the knee compared with their healthy counterparts. In addition, energy consumption was significantly higher in patients with OA (p = 0.009) than in healthy participants. However, margin of stability was significantly lower (p = 0.05) in patients with OA of the knee than in healthy subjects. These findings suggest that gait parameters and energy consumption assessments may be important in patients with OA of the knee. Therefore, clinicians are to be aware of these findings by developing appropriate gait rehabilitation for patients with OA of the knee.

Functional walking ability of paraplegic patients: comparison of functional electrical stimulation versus mechanical orthoses.

BACKGROUND: Spinal cord injury (SCI) can cause partial or complete paralysis of the lower extremities, impairing the ability of individuals to stand and walk. Various types of mechanical orthoses, functional electrical stimulation (FES) systems and hybrid orthoses that incorporate FES have been designed to restore the ability of individuals with SCI to stand and walk. Standing and ambulation performance of SCI subjects using these different systems have been previously evaluated using energy consumption analysis, stability analysis and by quantitative gait analysis. Though FES-based systems are technologically more complex than passive mechanical systems, it is not apparent whether user performance is substantially improved with FES and hybrid orthoses compared to purely mechanical orthoses. METHOD: An electronic search was performed via the Pubmed, Embase and ISI Web of Knowledge data base from 1960 to 2010. The abstracts, titles and full details of each individual study were assessed by the authors. The findings that were indicative of users' performance with the FES systems and hybrid systems were compared with that of mechanical orthoses. Moreover, the effects of using these different systems on physiological health were evaluated. RESULTS: Twelve original articles and 5 review articles were selected by the author. However, most of the original articles were case studies. The results of previous investigations indicate that user performance with the mechanical orthoses was generally better than that of the hybrid and FES systems based on subject's stability and energy consumption while walking. Moreover, subject reportedly experienced a higher incidence of problems with the use of hybrid orthoses and FES systems compared with mechanical orthoses. CONCLUSION: FES and hybrid orthoses offer considerable potential for restoring standing and walking abilities in persons with SCI. However, improvements in their designs and operation with subsequent objective evaluations are required to demonstrate that these systems enable users to improve their performance over that currently possible with passive, mechanical orthoses.

Investigating Glenohumeral Joint Contact Forces and Kinematics in Different Keyboard and Monitor Setups using Opensim.

Background: The musculoskeletal complaints of the shoulder are prevalent in people who work with computers for a long time. Objective: This study aimed to investigate the glenohumeral joint contact forces and kinematics in different keyboards and monitor setups using OpenSim. Material and Methods: Twelve randomly selected healthy males participated in an experimental study. A 3×3 factorial design was used in which three angles were considered for the monitor and three horizontal distances for the keyboard while performing standard tasks. The workstation was adjusted based on ANSI/HFES-100-2007 standard to maintain a comfortable ergonomic posture for controlling confounding variables. Qualisys motion capture system and OpenSim were used. Results: The maximum mean range of motion (ROM) of both shoulders' flexion and adduction was observed when the keyboard was 15 cm from the edge of the desk, and the monitor angle was 30°. The maximum mean ROM of both shoulders' internal rotation was recorded for the keyboard at the edge of the desk. Peak forces for most right shoulder complex muscles were obtained in two setups. 3D shoulder joint moments were significantly different among nine setups (P-value<0.05). The peak anteroposterior and mediolateral joint contact forces were recorded for the keyboard at 15 cm and the monitor at zero angles (0.751 and 0.780 N/BW, respectively). The peak vertical joint contact force was observed for the keyboard at 15 cm and the monitor at 15° (0.310 N/BW). Conclusion: The glenohumeral joint contact forces are minimum for the keyboard at 8 cm and the monitor at zero angles.

Evaluation of Various Fixation Methods in Acute Scapholunate Dissociation, A Finite Element Study.

Objective: This study aimed to compare the outcomes of fixing scapholunate with pins and screws in parallel, convergent, and divergent orientations. Materials and Methods: In this computer simulation study, the CT scan images of a healthy subject were used to construct a 3D model of the wrist joint using MIMICS software. The imposed force to scaphoid and 3D model lunate bones, as well as the scapholunate angle and distance, were compared in different surgical techniques using parallel, divergent, and convergent pins and screws. Results: In the absence of external force, the imposed stress applied to the scaphoid and lunate bones in cases of parallel pins and screws were 7.5MPa, 5.08MPa (pins), 1.134MPa, and 1.151MPa (screws), and 10.90MPa, 10.90MPa (pins), 9.7MPa, and 34.1MPa (screws) for 50N flexion force. The imposed stress in this approach is significantly lower compared to other interventions. Better outcomes were seen regarding scapholunate angle and scapholunate distance in using parallel pins or screws as well. Conclusion: In conclusion, implementing parallel pins and screws for scapholunate fixation had better results in terms of achieving carpal stability in scapholunate dissociation. However, fixation with pins and screws showed a statistically significant difference. Furthermore, a wide range of motion exercises with no additional forces can be used in the rehabilitation of patients undergoing this surgery.

Assessment of the effects of white cane variables on step symmetry of blind individuals.

BACKGROUND: Step symmetry is an important feature of human gait and is often regarded as a key index of healthy individuals' walking. This study evaluated the effects of height, white cane technique, and cane tip on symmetrical gait in blind individuals. MATERIALS AND METHODS: Twenty blind and ten sighted subjects, aged 15-38 years, participated in this study. The harmonic ratio (HR) and improved HR (iHR) were measured by trunk accelerometer as gait symmetry index in three axes: anteroposterior (AP), vertical, and mediolateral of the body. These parameters were measured in the sighted group in open-eye conditions and in the blind group in five experimental conditions with different two heights (standard and long), two tips (pencil and roller), and two techniques (two-point touch and constant contact) of white cane when they walked in the 6-m path. RESULTS: There was a significant difference between HR and iHR of the blind and sighted group, which indicates a significant reduction of symmetry loss in the blind group. Among the five different conditions studied in the group of blind people, an increase was observed in the HR and the iHR on the AP axis during the application of a standard cane with a roller tip, which indicated an increase in symmetry. CONCLUSION: Based on the results, a long cane with a pencil tip and a standard cane with a roller tip in the constant contact technique can increase step symmetry.

Custom-Made Ethyl Vinyl Acetate Insoles with Arch Support Could Improve Static Balance in Diabetic Women with Neuropathic Foot.

BACKGROUND: Individuals with diabetic neuropathy may experience plantar ulcers and postural instability. Although use of an insole with arch support has the potential to decrease the incidence of plantar ulcers, the choice of proper design and material density concerning postural stability is challenging. The objective of this pilot study was to conduct a preliminary evaluation of the immediate effects of custom-made ethyl vinyl acetate insoles with arch support and Shore A values of 30 or 50 on static balance in patients with diabetes and neuropathic foot/feet. METHODS: Ten women with diabetes participated in this study. Static balance was analyzed while in double-limb standing with eyes closed and eyes open and while standing on a dominant limb with eyes open wearing shoes only and wearing shoes and insoles with Shore A values of 30 and 50. RESULTS: With insole, the mean values of center of pressure excursions decreased significantly while standing on double limbs with eyes closed. The improvement in static balance was greater while using the insole with greater density; however, the difference was not statistically significant. CONCLUSIONS: An insole with arch support made of ethyl vinyl acetate Shore A of 30 and 50, which could decrease plantar pressure concentration, had no negative effect on the static balance of diabetes. Therefore, further research on the long-term effects of such insoles on the static balance of diabetes is suggested.

The influence of walking with an orthosis on bone mineral density by determination of the absolute values of the loads applied on the limb.

Spinal cord injury is damage to the spinal cord that results in loss of mobility and sensation below the level of injury. Most patients use various types of orthoses to stand and walk. It has been claimed that walking and standing with orthosis reduces bone osteoporosis, improves joint range of motion and decreases muscle spasm. Unfortunately, there are discrepancies regarding the clinical effects of walking and standing on bone mineral density. The aim of this research was to find the absolute values of the loads transmitted by body and orthosis in walking with use of an orthosis. 5 normal subjects were recruited to stand and walk with a new design of reciprocal gait orthosis. The loads transmitted through the orthosis and anatomy was measured by use of strain gauge and motion analysis systems. It has been shown that the loads applied on the anatomy were significantly more than that transmitted through the orthosis. Moreover, the patterns of the forces and moments of the orthosis and body completely differed from each other. As the most part of the loads applied on the complex transmitted by anatomy in walking with an orthosis, walking with orthosis can influence bone mineral density.

Evaluation of the gait performance of above-knee amputees while walking with 3R20 and 3R15 knee joints.

BACKGROUND: The performance of the subjects with above-knee amputation is noticeably poorer than normal subjects. Various types of components have been designed to compensate their performance. Among various prosthetic components, the knee joint has great influence on the function. Two types of knee joints (3R15, 3R20) have been used broadly for above-knee prostheses. However, there is not enough research to highlight the influence of these joints on the gait performance of the subjects. Therefore, an aim of this research was to investigate the performance of the above-knee amputees while walking with 3R15 and 3R20 knee joints. MATERIALS AND METHODS: 7 above-knee amputees were recruited in this research study. They were asked to walk with a comfortable speed to investigate the gait function of the subjects with 3 cameras 3D motion analysis system (Kinematrix system). The difference between the performances of the subjects with these joints was compared by use of paired t-test. RESULTS: The results of this study showed that, the performances of the subjects with 3R20 were better than that with 3R15. The walking speed of the subjects with 3R20 was 66.7 m/min compared to 30.4 m/min (P-value = 0.045). Moreover; the symmetry of walking with 3R20 was more than that with 3R15, based on the spatio- temporal gait parameters values (P-value <0.05). CONCLUSION: The difference between the performances of the subjects with 3R20 and 3R15 knee joints was related to the walking speed, which improved while walking with 3R20 joint.