Ossur Scientific E-letter

12 December 2007

Ossur Scientific E-letter Issue 4#2007

Össur Academy’s Scientific E-letter Issue 4#2007 (December 2007)

Dear readers,

Welcome to the fourth issue of our Scientific E-letter of 2007.
This E-letter includes ten different scientific papers. The articles cover the subjects of amputation/rehabilitation, prosthetics/biomechanics, orthotics/biomechanics, bionics and quality management.
Nine of the selected papers have been published in 2007 and one in 2006.

Enjoy the reading!

 

Amputation/Rehabilitation

Rau B. Bonvin F. de Bie R.
Short-term effect of physiotherapy rehabilitation on functional performance of lower limb amputees.
Prosthetics and Orthotics International, Volume 31, Issue 3 September 2007 , pages 258 – 270

There is a  large number of victims of landmines; many of them have traumatic lower limb amputations. The International Committee of the Red Cross recognised the need to rehabilitate these victims and was concerned about measuring the efficacy of physiotherapy as well as collecting data about the rehabilitation of amputees.

With the goal of comparing the effectiveness between a short, intensive physiotherapy program and standard care, Rau and colleagues performed this study. Altogether 58 male unilateral lower limb amputees were randomised equally over intensive care and standard care. The trial took place in a clinical location on the premises of the International Committee of the Red Cross, in Southern Myanmar.

The group receiving intensive physiotherapy followed a three day program consisting of seven specific exercises that lasted about one hour in total. The exercises included lower limb strengthening exercises, weight bearing, coordination tasks, corrected walking, obstacle management, and functional training. The control group received standard care, which meant mainly walking under supervision.

The two rehabilitation methods were assessed on: 2 minute walk test, physiological cost index (PCI), amount of weight bearing on both legs, five questions of the Functional Measure for Amputees questionnaire and the timed up and go test (TUG).

The group that had received intensive treatment showed significant improvement in the 2 minute walk test, in the PCI and in the maximal weight bearing test on the amputated leg.

This study demonstrates that research remains feasible even with limited resources in a developing country. The authors concluded that their study demonstrated that intensive physiotherapy is effective in improving the functional performance of lower limb amputees and therefore has a place in every rehabilitation centre.

Ebrahimzadeh M H. Rajabi M T.
Long-term Outcomes of Patients Undergoing War-related Amputations of the Foot and Ankle
The Journal of Foot & Ankle Surgery 46(6):429–433, 2007

Ebrahimzadeh and Rajabi found a lack of documentation of the long-term outcomes for patients with traumatic foot and ankle amputations. Therefore this study was performed on 27 Iranian soldiers requiring lower extremity amputations as a result of wartime trauma.

The study included a review of the patients’ wartime medical records, clinical examinations, and questionnaires completed by the subjects

The review indicated that the average time from amputation was 17.5 years. Land mines were the most prevalent (66.6%) cause of amputation. The prevalence of different clinical symptoms reported by the amputees at the time of their last follow-up was as follows:
• 40.7% phantom sensations
• 22.2% phantom pain
• 44.4% stump pain
• 44.4% back pain
• 33.3% contralateral knee pain
• 14.8% ipsilateral knee pain
• 74% reported treatment for psychological conditions.
• 48.1% were currently employed, or had been employed
for a number of years after the amputation
• 96% had children
• all of the patients were married

The study group found that the amputees were able to maintain a satisfactory family life, despite a significant high rate of long term pain, discomfort, psychological problems and the fact than less than 50% were employed.

Stepien J M. Cavenett S. Taylor L. Crotty M.
Activity levels among lower-limb amputees: self-report versus step activity monitor.
Arch Phys Med Rehabil. 2007 Jul;88(7):896-900.

The prescription of a prosthesis is partly based on the patient’s self reported activity level. If an incorrect device is prescribed a patient’s activity may be impacted. Stepien and collegues performed this study to evaluate evidence on the reliability of self reported activity level.

Seventy-seven unilateral lower-limb amputees were included in the descriptive study where the activity was objectively measured by a step activity monitor and compared with the self-reported level activity.

The result showed a poor agreement between the subjective and objective levels of activity in 66% of the patients.

The authors concluded that the majority of the participants were unable to correctly  report their own activity level in comparison with the measured activity level. They suggest that an objective measure of daily activity is more appropriate when prosthetic devices are being prescribed for individual amputees.

Prosthetics/Biomechanics

Fang L. Jia X. Wang R.
Modeling and simulation of muscle forces of trans-tibial amputee to study the effect of prosthetic alignment.
Clinical Biomechanics 22 (2007) 1125–1131

Fang and his study group intended, with muscle modeling and computer stimulation, to predict and explain the patterns of muscle forces in the stump of a trans-tibial amputee during walking. They also wanted to assess the effects of the prosthetic alignment.

Muscle forces of the stump were calculated by combining musculoskeletal modeling and computer simulation. The prosthesis was aligned to optimal position for the subject and then changed to ±6° in the sagittal plane. Kinematic data of the stump with prosthesis and ground reaction forces were simultaneously recorded by a gait analysis system and a force platform. The recorded data was put into a model of the lower trans-tibial extremity and the corresponding seven muscle forces were predicted.

The analysis showed that the activity of the muscles was higher in stance than in swing phase. During both heel-strike and toe-off most muscles appeared to be very active. The predicted muscle forces were similar  in temporal distribution at the three alignment conditions, but the major muscles such as gluteus maximus, hamstrings, vasti and rectus femoris generated remarkably greater forces in the mal-aligned condition than  in the normal condition. That could be explained in that the incorrect alignment would generate extra joint moments that have to be counteracted by more muscle force. The increased force costs more energy which might lead to fatigue. The authors conclude that  proper alignment is important for  normal activity of the stump muscles.

Orthotics /Biomechanics

Sahar T. Cohen MJ. Ne’eman V. Kandel L. Odebiyi DO. Lev I. Brezis M. Lahad A.
Insoles for prevention and treatment of back pain (Review)
Cochrane Database of Systematic Reviews 2007, Issue 4. Art. No.: CD005275. DOI: 10.1002/14651858.CD005275.pub2.

Shoe insoles are often used as treatment for back pain, one of the most common health problems in the industrialized world. This systematic Cochrane review was carried out by Sahar et al to gain theoretical and clinical knowledge and to determine the effectiveness of the use of insoles.

The review included six randomized controlled trials that met the inclusion criteria. The authors assessed the use of customized or non-customized insoles, for prevention or treatment of back pain, compared to placebo, no intervention or other interventions.

The result showed strong evidence that the use of insoles does not prevent back pain. There is limited evidence that insoles ease back pain or also shift the pain to the lower extremities.

The authors conclude that the literature in this area is limited and the studies are of poor quality, which may have influenced the outcome of this review.

MacLean C. McClay Davis I. Hamill J.
Influence of a custom foot orthotic intervention on lower extremity dynamics in healthy runners
Clinical Biomechanics 21 (2006) 623–630

About 40 millions North Americans are estimated to be recreational runners. Runners are among the most commonly injured athletes. Overuse injuries are regularly managed by custom foot orthoses and it is generally accepted that this therapeutic intervention gives positive clinical outcomes.

MacLean and his study group wanted to explore the influence of custom foot orthoses on the lower extremity dynamics of healthy runners. Three dimensional kinematic and kinetic data was collected on 15 female, frequent runners, while each subject ran with and without a custom foot orthotic in her running shoe. During stance phase selected maximum ankle and knee joint angles and moments were measured.

The trials showed that when the test subjects wore the custom foot orthotics, they demonstrated significantly decreased maximum values in rearfoot eversion angle, rearfoot eversion velocity and internal ankle inversion moment. Also decreases in the movements in the sagittal plane of the knee joint were found.

The authors conclude that it is still unclear how  custom foot orthotic intervention influences lower extremity dynamics to produce positive clinical outcomes, but a better understanding of the dynamic influence will not only improve prescription and manufacturing practices, but also shed light on the mechanisms that cause overuse injuries.

James Selfe, Jim Richards, Dominic Thewlis, Sean Kilmurray
The biomechanics of step descent under different treatment modalities used in patellofemoral pain.
Gait & Posture xxx (2007) xxx–xxx article in press

Patellofemoral taping techniques are today considered  part of standard
clinical practice to relieve patellofemoral pain despite an ongoing debate about the mechanical effects of taping. Recent work has highlighted the importance of the proprioceptive effects of taping. Research on the effects of bracing in the management of patellofemoral problems is limited compared to research on taping. Most previous work on the use of knee bracing and taping has focused on sagittal plane movement. However, most bracing and taping techniques aim to modify patellar movement in the coronal and transverse planes.

Selfe and collegues studied the three-dimensional mechanics of the knee during a controlled eccentric step down task, in which the twelve study subjects had no intervention, neutral patella taping and patellofemoral bracing.

The mechanical analysis revealed that the patellofemoral bracing and taping led to a significant reduction in the maximum coronal plane and range of torsional knee angles. The ranges of coronal and transverse plane knee moments were also significantly reduced. Furthermore the study group found that the brace proved to be more effective in the coronal and transverse planes in comparison to taping or no intervention.

Bionics

Tonet O. Marinelli M. Citi L. Rossini P M. Rossini L. Megali G. DarioP.
Defining brain–machine interface applications by matching interface performance with device requirements
Journal of Neuroscience Methods xxx (2007) xxx–xxx article in press.

Brain–machine interfaces (BMIs) have so far been studied as a way to communicate for people who have little or no voluntary control of muscle activity. In this context, low-performing interfaces can be considered as prosthetic applications. For able-bodied users, a BMI would only be practical if conceived as a supplementary interface. In this paper Tonet et al introduced a method for pointing out effective combinations of interfaces and devices for creating real-world applications. Devices for domotics (= applied Information and Communication Technologies for more Comfort and Convenience in and around the Home), rehabilitation and assistive robotics are described. This article also presents how Human-Machine Interfaces (HMIs) are classified and describe their performance in terms of throughput and latency. Finally device requirements are matched with performance of available interfaces.

It was found that simple rehabilitation and domotics devices could be easily controlled by means of BMI technology. Prosthetic hands and wheelchairs are suitable applications but do not attain optimal interactivity. Regarding humanoid robotics, the head and the trunk can be controlled by means of BMIs, while other parts require too much throughput. Robotic arms, which have been controlled by means of cortical invasive interfaces in animal studies, could be the next frontier for non-invasive BMIs. Combining smart controllers with BMIs could improve interactivity and boost BMI applications.

Quality Management

Cole, Mary Jane, Durham, Sally and Ewins, David (2007)
An evaluation of patient perceptions to the value of the gait laboratory as part of the rehabilitation of primary lower limb amputees.
Prosthetics and Orthotics International 2007; 1 - 11

It is well understood that there is a value to gait analysis for research and product development/evaluation. Today however, when rehabilitating amputees in the clinical setting, the application of gait analysis beyond visual observation is not routinely practiced. This is mainly a result of the cost and time it takes to complete a fully instrumented data collection and analysis. It has been found thatclinicians do not have a problem recognizing  how the patient should improve his or her gait but more a problem with informing the patient about how to do it.

To address these problems a weekly clinical gait service for primary amputees, based on a reduced data set from video and video vector technology, was developed. Primary amputees were seen twice in the gait laboratory during their rehabilitation period, with an appointment time for each patient set at 15 minutes, to cover both data collection and review.

To evaluate the method and the patients’ perceptions of the gait clinic a questionnaire was completed by 48 primary amputees over a 6-month period. The aim of the study was to address the patients’ view of the gait clinic. Cole and her study group wanted to know the following: whether the information and instructions provided were adequate, if they found the process of being observed unsettling in any way, were the sessions useful and if so, what was useful and did the sessions highlight information that would be relevant to their rehabilitation.

The results from the questionnaire demonstrated that the clinic was perceived positively by the patients. The authors concluded that the approach offers benefits to patients and may also be used as a teaching method for clinicians working in amputee rehabilitation.

Gallagher P. Desmond D.
Measuring quality of life in prosthetic practice: benefits and challenges.
Prosthet Orthot Int. 2007 Jun;31(2):167-76.

There is an increasing awareness that, as an outcome, measuring quality of life is important to ensure a patient centred and holistic approach. Gallagher and Desmond completed this review to outline the benefits of quality of life as an outcome measurement in assessing prosthetic treatment.

Quality of life is an abstract, complex and multidimensional issue that is difficult to define and maybe even more difficult to measure. This paper introduces the key concepts and challenges in the definition and assessment of quality of life post-amputation. It includes the relative advantages and disadvantages of adopting generic, disease/condition specific, dimension specific and individualized measures of quality of life.

The review defines and recommends issues and guidelines for reflection when performing quality of life research and assessment. The authors conclude that a co-ordinated approach by clinicians in the field of prosthetics is necessary to ensure that quality of life will become an outcome measure and also to ensure its measurement in a standardized and rigorous manner.

Össur Academy wishes you a wonderful holiday season and is looking forward to providing you with more interesting scientific news next year!

Thanks for reading,
Össur Academy.

 

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