The initiation of gait in lower limb amputees: some related data

The initiation of gait, from balanced standing position to the toe-off of the stance leg, was analyzed in 8 unilateral above-knee (AK) and 10 unilateral below-knee (BK) males amputees. Thirty-one parameters were measured, including ground-foot forces and the movements and timing of hip, knee, and ankle joints. The significant changes from the normal pattern of initiation of gait found in the AK and BK amputees, as well as significant changes between the two amputees groups themselves, are described. The amputees were divided into two subgroups: those who start walking with their prosthesis and those starting with their normal leg. The two groups were compared statistically for each amputation level and all were compared to a normal subjects group. Differences relating to the choice of the swing leg were found. The findings are reported as part of a future databank.     

双侧髋关节离断假肢交互步态行走机构的研究

目的设计一种与双侧髋关节离断假肢其他配件连接的交互步态行走机构。方法将截瘫患者用矫形器交互步态行走原理应用于双侧髋关节离断假肢交互步态行走机构中,为1例截肢者安装交互步态行走假肢,并与穿普通加拿大式双髋离断假肢摆过步态的行走速度和能量消耗进行比较。结果患者穿交互步态行走假肢交互步行比穿普通加拿大式双髋离断假肢摆过步行能量消耗少,且减轻上肢负荷,行走外观更接近常人;后者比前者行走速度快,但是能耗高。结论本截肢者交互步态行走假肢比传统假肢步行能量消耗少,行走外观更接近常人。     

A comparative evaluation of oxygen consumption and gait pattern in amputees using Intelligent Prostheses and conventionally damped knee swing-phase control

OBJECTIVE: To compare the gait of amputees wearing conventionally damped pneumatic swing-phase control knees and microchip-controlled Intelligent Prostheses. DESIGN: Crossover trial. SETTING: An amputee rehabilitation centre in a teaching hospital. PARTICIPANTS: Ten established unilateral transfemoral prosthetic users were asked to participate in the trial; all agreed. INTERVENTIONS: The amputees were assessed wearing pneumatic swing-phase control knees and then with the Intelligent Prosthesis. MAIN OUTCOME MEASURES: Oxygen consumption while walking at different speeds on a treadmill, video-recording of gait assessed by a panel and temporal-spatial parameters of gait whilst walking at slow, fast or normal speeds in a gait laboratory. RESULTS: Mean oxygen cost for all subjects at 0.69 m/s was 0.33 ml/kg.m with the conventional limb and 0.30 ml/kg.m with the Intelligent Prosthesis (p = 0.01). At 1.25 m/s the mean oxygen cost for the conventional limb was 0.24 ml/kg.m and for the Intelligent Prosthesis was 0.22 ml/kg.m (not significant). The ANOVA analysis showed that oxygen cost was similar at normal walking speeds but increased more at lower speeds for the pneumatic swing-phase control leg compared to the Intelligent Prosthesis (p < 0.02). There were no significant differences in subjective gait evaluation or temporal and spatial gait parameters. CONCLUSION: At lower speeds oxygen cost was lower with the Intelligent Prosthesis. Gait analysis detected no significant changes between the two legs.     

Prosthetic rehabilitation of geriatric amputee patients: a follow-up study

During a four-year period, 116 lower extremity amputee patients older than 65 years were evaluated and treated by our department. Fifty-nine patients with below-knee (BK) amputations, 22 with above-knee (AK) amputations, and 15 with bilateral amputations were fitted with prostheses and trained in their use. A follow-up study on all patients was done at an average of 22 months after they had completed their training program but not earlier than after 6 months. Of all BK amputees who had been fitted with a prosthesis, 73% were using it fulltime and as their main mode of locomotion; 25% were using it part of the time. The results were less favorable for AK and for bilateral amputee patients: 50% of AK amputees and 33% of the bilateral amputees had become fulltime users of their prostheses. Age alone was not a major determining factor in success or failure of prosthetic rehabilitation. Failures usually were due to concurrent medical disease or mental deterioration. The study indicates that the effort and expense of fitting and training geriatric patients with prostheses may be well worthwhile.     

Amputation: energy cost of ambulation.

A mobile instrument system was used to measure energy consumption by indirect calorimetry at rest and during ambulation in 25 unimpaired subjects, 6 unilateral below-knee (BK) amputee patients, 6 unilateral above-knee (AK) amputee patients and 4 bilateral AK amputee patients. To prevent the introduction of gait difficulties among the impaired subjects, each subject was permitted to walk at his own comfortable speed. Since speed thus varied among subjects, ambulation data were expressed in units of energy per foot traveled. Statistical analyses of the mean oxygen costs indicated several significant differences among the groups. In comparison to unimpaired subjects, the mean oxygen consumption was 9% higher in unilateral BK amputee patients, 49% higher in unilateral AK amputee patients and 280% higher in bilateral AK amputee patients.     

Dynamic analysis of above-knee amputee gait

BACKGROUND: It is important to understand the characteristics of amputee gait to develop more functional prostheses. The aim of this study is to quantitatively evaluate amputee gait by dynamic analysis of the musculoskeletal system during level walking and stair climbing. METHODS: Dynamic analysis using gait analysis, electromyography and musculoskeletal modeling for above-knee amputees (n=8) and healthy adults (n=10) was performed to evaluate the muscle balance, muscle force, and moment of each major muscle in each ambulatory task. Time-distance parameters and the kinematic parameter of gait analysis were calculated, and a root mean square electromyogram of major muscles and hamstring and tibialis anterior coactivity was measured using electromyography. Lastly, dynamic analyses of above-knee amputee gaits were performed using musculoskeletal models with scaled bones and redefined muscles for each subject. FINDINGS: Most kinematic parameters showed statistically no difference among the tasks, excluding pelvic tilt, pelvic obliquity, and hip abduction. Major muscle activities and coactivities of the hamstring and tibialis anterior showed that the stair ascent task needed more muscle activity than the stair descent task and level walking. The muscle activity and coactivity of amputees were greater than those of healthy subjects, excluding the hamstring coactivity during stair ascent (P<0.05). Lastly, dynamic analysis showed that weakened abductor and excessive adductor and then inadequate torque during all tasks were quantitatively observed. INTERPRETATION: Dynamic analysis of amputee gait enabled us to quantify the contribution of major muscles at the hip and knee joint mainly in daily ambulatory tasks of above-knee amputees and may be helpful in designing functional prostheses.     

Causes and correction of abnormal gait patterns due to prosthesis in above-knee amputees

Abnormal gait patterns cause an increase in the energy cost of walking in above-knee amputees. Disturbances of the walking pattern are often caused both by the amputated patient himself and by incorrect prosthetic fitting. The early detection and correction of causative factors is of great importance for successful rehabilitation of these amputees. During the follow-up examinations the prosthesis must be inspected for a correct fitting and individually appropriate knee stabilizing components. Prior to any corrective measures it must be excluded that the artificial limb has been put on incorrectly by the amputee himself.     

双小腿截肢者假肢辅助下行走能力的评价

目的比较双小腿截肢者穿戴假肢的行走能力与正常人的差别,制定双小腿截肢者穿戴假肢行走能力参考指标。方法选择11 例双小腿截肢者作为截肢组,12 名健康成年人作为对照组,分别进行室内步态分析测试、室外行走1 km所用时间及能量消耗测试、静态站立平衡能力测试。结果室内步态分析测试中,截肢组自我感觉最舒适平均速度为1.07 m/s,对照组为1.29m/s。当受试者以自我感觉最舒适的速度行走时,截肢组部分步态时空参数与对照组存在显著性差异(P<0.05);室外行走1 km所用时间及能量消耗与对照组存在显著性差异(P<0.05);静态站立平衡与对照组比较无显著性差异(P>0.05)。结论双小腿截肢者与正常人的行走能力存在差异,对截肢者行走能力定量的评价能够为截肢者的康复提供更准确的参考。     

Gait patterns of transtibial amputee patients walking indoors barefoot

OBJECTIVE: To evaluate the gait patterns of lower limb amputee patients walking with and without shoes and to identify differences in barefoot gait patterns when using different prosthetic feet. DESIGN: Optoelectronic three-dimensional motion analysis of gait was performed on six transtibial amputees using a solid ankle cushion heel foot and a single-axis foot, both with and without shoes. RESULTS: Gait abnormalities were observed during barefoot walking when the solid ankle cushion heel foot was used. These included knee joint hyperextension of 9.9 +/- 2.0 degrees and the loss of ankle plantar flexion in the early stance phase. When the single-axis foot was used, knee flexion thrust declined from 9.9 +/- 3.7 degrees to 7.2 +/- 3.8 degrees and ankle plantar flexion decreased from 9.9 +/- 2.8 degrees to 7.0 +/- 2.1 degrees during the early stance phase. CONCLUSIONS: In transtibial amputees, significant gait abnormalities were observed during barefoot walking using the solid ankle cushion heel foot. These gait patterns improved, however, with use of a single-axis prosthetic foot, which permits a further plantar flexion after the initial contact.     

The gait initiation process in unilateral lower-limb amputees when stepping up and stepping down to a new level

BACKGROUND: Unilateral lower-limb amputees lead with their intact limb when stepping up and with their prosthesis when stepping down; the gait initiation process for the different stepping directions has not previously been investigated. METHODS: Ten unilateral amputees (5 transfemoral and 5 transtibial) and 8 able-bodied controls performed single steps up and single steps down to a new level (73 and 219 mm). Duration, a-p and m-l centre of mass and centre of pressure peak displacements and centre of mass peak velocity of the anticipatory postural adjustment and step execution phase were evaluated for each stepping direction by analysing data collected using a Vicon 3D motion analysis system. FINDINGS: There were significant differences (in the phase duration, peak a-p and m-l centre of pressure displacement and peak a-p and m-l centre of mass velocity at heel-off and at foot-contact) between both amputee sub-groups and controls (P<0.05), but not between amputee sub-groups. These group differences were mainly a result of amputees adopting a different gait initiation strategy for each stepping direction. INTERPRETATION: Findings indicate the gait initiation process utilised by lower-limb amputees was dependent on the direction of stepping and more particularly by which limb the amputee led with; this suggests that the balance and postural control of gait initiation is not governed by a fixed motor program, and thus that becoming an amputee will require time and training to develop alternative neuromuscular control and coordination strategies. These findings should be considered when developing training/rehabilitation programs.     

Détermination de la puissance interne au cours de la marche de personnes amputées fémorales. Influence de la vitesse

The energy consumption of transfemoral amputee is increased compared with asymptomatic people. Internal power during gait at different walking speeds can help to understand this phenomenon. Eight transfemoral amputees and six asymptomatic subjects participated in this study. Internal power of each lower limb was computed and it demonstrated an asymmetry between the two lower limbs of the patients. The method proposed to calculate internal work has the main advantage that it allows to differentiate the work performed by each limb. This is particularly interesting for patients with very asymmetric gaits like amputees.     

Oxygen consumption of elderly persons with bilateral below knee amputations: ambulation vs wheelchair propulsion

Elderly bilateral below knee (BK) amputees were tested for oxygen consumption (VO2), heart rate (HR) and velocity (V) during ambulation on a 40m walkway and a stationary wheelchair ergometer. Values obtained from amputees were compared to values obtained from a control population of the same age group. On test day 1 bilateral amputees and normal subjects ambulated at their natural pace on a walkway for approximately 5 minutes. On test day 2 each subject propelled a stationary wheelchair ergometer at their natural rate for the same distance that they ambulated. Measurements of VO2 (ml/m/kg), HR (beats/min), and V (m/min) were obtained during both sessions. Results show that the bilateral BK group required significantly more VO2 (ml/m/kg) (123%), had higher HR (26%), and slower V (36%) than the normal group during ambulation. The energy cost in terms of ml/min/kg during ambulation was similar, suggesting that the amputees ambulated at the same power cost as normals but at lower velocities. During wheelchair propulsion the BK group and normal group showed no significant difference in the 2 criteria. Results suggest that wheelchair propulsion is a more energy efficient mode of mobility for elderly bilateral BK amputees than ambulation. Energy cost and heart rate determinations may be valuable in choosing the course of mobility training and recommended activity levels. Cosmetic, psychosocial, and other clinical factors must be considered in prescribing rehabilitation.     

Improved ankle-foot system for above-knee amputees

Above-knee amputees were studied while wearing a prosthesis containing either a standard or a modified single axis foot. The modified foot allowed 12-15 degrees of dorsiflexion and reduced stiffness in the area of the metatarsal-phalangeal (MTP) joint. The amputees were allowed to vary the stiffness at the two joints to obtain what "felt best." The amputees agreed that in comparison to the standard single-axis foot, the modified foot: a) offered a more comfortable gait while walking on level ground; b) made walking up inclines easier; c) affected knee stability while walking on declines; and d) made foot placement on stairs and ladders more critical due to potential knee instability. As well as qualitative reactions, changes in the gait cycle were measured quantitatively for different speeds and inclinations of walking on a treadmill. Measurements from normal subjects matched by age and sex were used for control purposes. All participants wore soft-soled shoes. The amputees selected a stiffness that allowed a degree of dorsiflexion which precisely matched on average that of the normal subjects. In contrast, they selected a stiffness at the MTP joint which allowed very little flexion of the toes. Significant changes also occurred in the pattern of hip movements, so that they became much more symmetrical on the two sides, although substantial differences remained between the hip movements of the amputees and the normal subjects. If modifications in the ankle joint can be coupled with improvements in the knee joint to prevent potential instability, a much improved gait should be possible for above-knee amputees.     

Three-dimensional motions of trunk and pelvis during transfemoral amputee gait

Goujon-Pillet H, Sapin E, Fodé P, Lavaste F. Three-dimensional motions of trunk and pelvis during transfemoral amputee gait.

Objectives

To identify characteristics of upper-body kinematics and torque transmission to the ground during locomotion in a group of patients with transfemoral amputation as compared with a group of asymptomatic subjects; and to investigate the influence of walking velocity and residual limb length on several characteristics of upper-body motion.

Design

Three-dimensional gait analysis with an optoelectronic device.

Setting

Gait laboratory.

Participants

Twenty-seven patients with transfemoral amputation and a control group of 33 nondisabled subjects.

Interventions

Not applicable.

Main Outcome Measures

Three-dimensional kinematics of the pelvis and the thorax and ground reaction force for amputees and control subjects.

Results

For subjects with transfemoral amputation, it was observed that upper-body angular ranges of motion (ROMs) increased globally as walking velocity decreased. For these subjects, specific patterns of pelvic rotation and torque transmission by the lower limbs around the vertical axis were found. The counter-rotation between the pelvic and scapular girdles was reduced. This reduction proved to be linked with the decrease of walking velocity. Walking velocity also affected all the parameters describing the motion of upper body. Pelvic ROM increased with the length of the limb decreasing.

Conclusions

The huge differences found between subjects with and without amputation suggest that the motion of the upper body must be considered to enhance gait.     

Evaluation of amputees]

INTRODUCTION: Review of the literature about evaluation of amputees. MATERIALS AND METHODS: A search of the Medline and Reedoc databases with the key words lower limb amputee, upper limb amputee, evaluation of lower limb amputee, evaluation of upper limb amputee, survey of lower limb amputee, survey of upper limb and the same words in French for reports on the evaluation of amputees. RESULTS: Evaluations of amputees differ according to the level of amputation (lower or upper limb) and age (adult or child). They concern standing balance, walking (lower limb) and the mono- or bimanual prehensile capacities with or without prostheses in daily living activities and leisure (upper limb) as well as quality of life, personal satisfaction, psychological impact and, in particular, coping strategies. DISCUSSION: For lower-limb amputees, tools to evaluate include scales of deambulation, of which few are valid in French, and global scales (on locomotor capacities, quality of life and satisfaction), which have been recently validated, but only one of them is valid in French. For upper-limb amputees, specific and valid tools are not available for adults; however, for children some functional capacity scales in daily activities have been validated and take into account psychomotor development. None of these tools are valid in French, and their use is scattered and limited to validation studies. CONCLUSION: Only a few tools to evaluate amputees are valid in French for adults, and they concern lower-limb amputees only. Validating some of these tools in French is necessary.     

Energy cost of walking of below-knee amputees having no vascular disease.

Fifteen unilateral below-knee amputees with no preexisting vascular disease were studied during free velocity walking to determine energy expenditure with and without a prosthesis. Expired air was collected, and heart rate and respiratory rate data were telemetered. Mean velocity for the unrestrained walking was 71 m/min, both during ambulation with a prosthesis and during crutch walking (without a prosthesis). Heart rates were within normal ranges during prosthetic walking (106 beats/min), but rose significantly to 135 beats/min for crutch walking. Energy cost also rose significantly from a mean of 15.5 ml O2/kg/min with a prosthesis of 22.3 ml O2/kg/min with crutches. The oxygen uptake measured in units of ml O2/kg/m increased when the subjects walked faster or slower than their free cadence. We concluded that the use of the prosthesis should be encouraged and that the amputee should be allowed to choose his natural velocity of walking.     

Normal and pathological human gait analysis using miniature triaxial shoe-borne load cells

Miniature triaxial shoe-borne load cells are used to analyze the normal and a below knee amputee's gait. The gait of an amputee is studied from first step on a temporary pylon to a final "normal" gait on a permanent prosthesis. The amputee's gait is compared to that of the normal subject. The load cells are an effective method of analyzing normal and abnormal gait. For an amputee, it is possible to identify misalignments from the output of the various load cells. This method may also be useful for identifying and correcting problems in the painful below knee stump. These load cells are further used to compute the center of pressure of a normal subject and a below knee amputee. Analysis of the resulting patterns has been found to be extremely useful as a measure of the subject's functional mobility.     

Influence of terrain on metabolic and temporal gait characteristics of unilateral transtibial amputees

The difficulties confronted by amputees during overground walking are rarely investigated. In this study, we evaluated, in real-world situations, the influence of ground surface on walking in young, active amputees by measuring temporal and spatial gait parameters (free walking speed [FWS], step length [SL], step rate), energy expenditure (EE) (e.g., oxygen uptake, oxygen cost [O(2)C]), and Rating of Perceived Exertion (RPE). Ten active transtibial amputees and ten nondisabled control subjects walked at self-selected speeds on three types of ground surface (asphalt, mown lawn, and high grass). No significant differences were observed between the two groups on asphalt and mown lawn. Differences between nondisabled subjects and amputees occurred for FWS (p = 0.03) and O(2)C (p = 0.04) on asphalt and mown lawn and for all variables in high grass. When amputees (even though very active) were exposed to a particularly difficult environment, their FWS decreased (p = 0.008) and their EE and RPE increased (p = 0.005) compared with nondisabled subjects. In high grass, both groups reduced their self-selected speeds (-15% for control subjects and -16% for amputees). Control subjects reduced their velocity by reducing both SL (-8.7%) and cadence (-7.1%), whereas amputees reduced their velocity by reducing SL (-17%) only.     

Chronic low back pain in traumatic lower limb amputees

OBJECTIVE: To ascertain the prevalence of back pain amongst traumatic lower limb amputees attending a regional rehabilitation centre and to determine the possible causes of back pain. DESIGN: All traumatic lower limb amputees given a semi-structured questionnaire to complete and a comparative subgroup of amputees with back pain and without back pain underwent physical examination, gait analysis, magnetic resonance scanning (MRI) and gait/standing stability analysis. SETTING: A subregional amputee rehabilitation centre. RESULTS: Transfemoral amputees were more likely to suffer from back pain (81 %) than transtibial amputees (62%) (p<0.05) and of those suffering from severe back pain, 89% and 81% also suffered from severe pain in the phantom limb and severe stump pain respectively. In two comparative subgroups of amputees there was no significant difference between back pain and pain-free groups except those with pain were more likely to have a body mass index (BMI) ratio above 50% of the recommended ratio. No difference in degeneration or disc disease between the groups on MR scans was found. Impact ground reaction forces during walking, irrespective of limb, were significantly greater (p < 0.05) in the pain-free group than in the pain group, as was walking speed. Gait asymmetry measures were similar in both groups. Centre of pressure displacement measures during standing were greater in the pain group than in the pain-free group. CONCLUSIONS: Low back pain in amputees is a significant problem equal to that of pain in the phantom limb and a biomechanical (myofascial) rather than a degenerative aetiology is suggested.