Prosthetics and Orthotics International

Outcome measures are becoming increasingly important in health care. Functional outcome measures are of particular importance for lower limb amputees since much of the rehabilitation process is concerned with increasing mobility and personal independence.

The Scottish Physiotherapy Amputee Research Group (SPARG) has used three measures of functional outcome: the Barthel Index, Russek's classification and the Locomotor Index. The review reported here involves 938 patients having a primary amputation at the transtibial or transfemoral level between October 1992 and July 1997. Differences in function due to age and level of amputation are well known clinically and the measures were compared by looking at their ability to detect these differences.

The Barthel Index lacked sensitivity because of ceiling effects and should not be considered as a suitable functional outcome measure for amputee patients. Russek's classification does detect significant differences but requires a large number of patients making it unsuitable for single hospital investigations. The Locomotor Index demonstrates significant differences due to age and amputation level despite fewer patients being assessed by this measure during the period covered by this paper. The range of the Locomotor Index can be extended to cover more active amputees by considering its ‘advanced activities’ subscale separately.

The Locomotor Index is a promising measure and should be considered by rehabilitation teams looking for a valid, reliable and sensitive functional outcome measure for use with lover limb amputees.

The purpose of this study was to investigate the properties of the flexible pressure sensor under laboratory conditions simulating the internal environment of the total surface bearing (TSB) socket to determine optimal conditions for measuring normal stresses on the stump. The equipment used in the study was the Pressure Distribution Sensor System for Sockets. In a climatic chamber maintained at 37d`C and 70% humidity the sensor sheet was mounted on a measuring apparatus loaded with three 10 kg weights, and output from the sensor was records after loading was adopted as the measured output. Output was greater when weight was decreased than when weight was increased because of hysteresis (paired t-test, p<0.05). The sensor had temperature sensitivity but differences in output were not statistically significant (paired t-test, 0.10>p>0.05). There were no significant differences in output among five sensor sheets or among five sections of four sensor sheets (two-way ANOVA, p>0.05), but repeated loading on the same section of the sensor sheet increased output (two-way ANOVA, p<0.05). Reproducibility and sensitivity distribution of the sensor are considered satisfatory under laboratory conditions, but measurements of rapid and repetitive movements may not be accurate and comparing subtle changes in output from a single sensor is not suitable. The reliability of the sensor in a clinical setting for measuring normal stresses on the stump with the TSB socket should be examined.

Force sensing resistors (FSR) have been used to measure dynamic stump/socket interface pressures during the gait of a trans-tibial amputee. A total of 350 pressure sensor cells were attached to the inner wall of a patellar-tendon-bearing (PTB) socket. Data was sampled at 150 Hz during the approximate 0.8 seconds of prosthetic stance of gait. A total of 42,000 pressures were recorded during a single prosthetic stance. This paper describes the distribution of the pressure patterns monitored during the prosthetic stance phase of gait.

As a result of deficiency at birth, disease or trauma, there are people who have no limbs from the hip joint downwards. These people have no possibillity of locomotion without the use of other devices such as wheelchairs or hip disarticulation prostheses.

As these prostheses are used by people of all ages, people who are different in their grade of physical activities and their weights, the prostheses are subject to different stresses related to these different circumstances.

The European Level 2 Draft Standard prEN 12523: 1966 “External limb prostheses and external orthoses — requirements and test methods” contains strength requirements for lower limb prostheses. These requirements shall be verified, where appropriate, by the application of the International Standard ISO 10328 “Prosthetics — Structural testing of lower limb prostheses” and ISO/FDIS 15032 “Prosthetics: Structural testing of hip prostheses”.

In order to allow the prostheses to be tested to the stresses that are experienced in real life, it is necessary to measure the stress that is induced in the prostheses while the patient is in an everyday situation, such as walking on level floor, walking on grass and/or walking on an uneven surface.

This work is concerned with the acquisition of loads generated in hip units of hip disarticulation prostheses by amputees during various activities. More than 30 patients were tested in Germany, France, and Belgium. The measurements were carried out with financial support from the European Commission and coordinated by the secretariat of CEN TC 293.

There is currenty a distinction drawn between a prosthesis considered to be provided for purely cosmetic reasons and a functional prosthesis provided to enable the amputee to achieve basic hand function. Using video analysis the study reported in this paper demonstrates that for non-manipulative actions cosmetic prostheses are actively used in the performance of everyday tasks as frequently evidence for a cosmetic prosthesis to be presented to an amputee as a realistic initial prosthesis and not as the option of last resort if a functional prosthesis is rejected. It is also recommended that training is provided in the use of cosmetic prostheses in two-handed tasks.

Initial analyses from a survey of people with unilateral upper limb congenital absence registered with the Cambridge Disablement Services Centre (DSC) indicated differences related to laterality and gender. A postal survey of all DSCs in the UK was conducted and support for these findings was provided from the analysis of the information supplied by the 25 DSCs who could provide data in the format requested. Comparing statistics for the UK population with those gained from the 25 DSCs, estimates for the number of children and adults who should be registered with DSCs in the UK are made. From these figures it is suggested that the non-registration rate for adults with a congenital absence of an upper limb could be as high as 64%.

The authors have developed a knee-ankle-foot orthosis with a joint unit that controls knee movements using a microcomputer (Intelligent Orthosis). The Intelligent Orthosis was applied to normal subjects and patients, and gait analysis was performed. In the gait cycle, the ratio of the stance phase to the swing phase was less in gait with the knee locked using a knee-ankle-foot orthosis than in gait without an orthosis or gait with the knee controlled by a microcomputer. The ratio of the stance phase to the swing phase between controlled gait and normal gait was similar. For normal subjects the activity of the tibialis anterior was markedly increased from the heel-off phase to the swing phase in locked gait. The muscle activities of the lower limb were lower in controlled force in locked gait showed spikes immediately after heel-contact in the vertical at heel-contact in the sagittal to locked gait, gait with the Intelligent Orthosis is smooth and close to normal gait from the viewpoint of biomechanics. Even in patients with muscle weakness of the quadriceps, control of the knee joint using the Intelligent Orthosis resulted in a more smooth gait with low muscle discharge.

The prescription of treatment systems which include orthoses to enable patients with high level thoracic spinal lesions to walk reciprocally is now widely practised. It remains a clinical option for which the efficacy is frequently called into question. A broad range of experience has now been accumulated with orthoses of this type, and this is reflected in the literature. The indications for prescription and outcomes of treatment have, as a result of the reported research, become clearer. However, the length of time over which the relevant work has been published and the variety of journals in which it has appeared makes it difficult to perceive a coherent message.

This review analyses the published work in order to identify the degree to which the therapeutic benefits which can accrue from ambulatory activity produce an economically justified outcome. Provided appropriate supply procedures are observed so that good patient compliance with the treatment is achieved, there is strong evidence that fewer pressure sores and improved independence will occur at a level where real overall cost savings can be made.

Factors which affect patient compliance and on which research findings have been published are identified. Comparisons are made between different orthoses with regard to these, so that more informed choice, taking into account preferences of individual patients, can be made by clinicians.

Two male trans-femoral amputees using modular trans-femoral prostheses lost control and fell to the ground when their prosthetic knees gave way. The semi-automatic knee lock malfunctioned in the first case while the free knee stabilising mechanics gave way in the second case. This resulted in a high tensile force acting on the contralateral quadriceps muscle causing it to rupture. As there are a significant number of patients with both kinds of prostheses it is important to be aware of this possibility so that necessary actions can be taken to minimise its occurrence. Even with the currently available weight activated stance phase control, the prosthetic knee will give way if the knee is flexed more than 20d` on weight bearing. Good power and control of hip extensors on the amputation side is needed to control the prosthetic knee joint, especially in the early stage of the walking cycle, i. e., from heel strike to mid-stance. Quadriceps muscle injury in amputees, as far as the authors are aware, has not been reported previously.

A multiple amputee more severe than a triple amputee is uncommon. There have been no reports on the rehabilitation outcome of a triple amputee, including hip disarticulation and transtibial amputation. The authors report the rehabilitation of a patient with left hip disarticulation, right transtibial amputation, and left trans-humeral amputation due to a train accident. He has successfully completed the rehabilitation programme and has become independent in prosthetic ambulation, activities of daily living, and driving.

Since the improvement of surgical oncological operative procedures, anaesthesiology and intensive care facilities, forequarter amputations are being performed with increasing frequency and decreasing morbidity and mortality. This clinical note reports the rehabilitation and prosthetic management of a patient with an extensive forequarter amputation including pneumectomy.

A “Proff of concept” prototype of a new device to link bilateral knee-ankle-foot orthoses, the Morring Medieal Linkage Orthosis (Moorong MLO), is presented. The device consists of an acuate sliding link centred on the hip joints with rolling element bearings to minimise friction. A sigle repeated-measures case study is reported in which a woman with an incomplete C6 tetraplegia ambulaetd over different surfaces and gradients using both the Moorong MLO and the Walkabout orthosis. Results demonstrated a slight increase in gait velocity in the Moorong MLO (between 0.36-1.02m/min faster) and a consistently lower oxygen cost across all conditions (between 18-61% reduction) compared was most noticeable on sloping surfaces. These preliminary results suggest an improved efficiency of ambulation in the new device.

Physiotherapie und Prothetik nach Amputation der unteren Extremität, Gertrude Mensch, Wieland Kaphingst, Springer Verlag, Berlin/Heidelberg/New York, 1998