Enhancement of a prosthetic knee with a microprocessor-controlled gait phase switch reduces falls and improves balance confidence and gait speed in community ambulators with unilateral transfemoral amputation (original) (raw)
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Journal of rehabilitation research and development, 2014
The benefits of microprocessor-controlled prosthetic knees (MPKs) have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3) with a transfemoral amputation (TFA). A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2) may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% fa...
JPO Journal of Prosthetics and Orthotics, 2009
Objective: To evaluate perceived comfort, security, maneuverability, cosmetic attributes, adverse effects, and safety of the microprocessor controlled C-Leg and nonmicroprocessor controlled passive prosthetic knees. Design: Nonrandomized pretest/posttest self-reported assessment with 50-question survey instrument. Setting: Six hundred Hanger Prosthetics and Orthotics facilities. Participants: Three hundred sixty-eight unilateral transfemoral amputees. Main Outcome Measures: Socket fit, confidence/security, gait and maneuverability, physical attributes, physical effects, and negative attributes/limiting factors of the two prosthetic technologies. Results: Participants characterized the C-Leg microprocessor controlled prosthesis as "better" according to the response percentages with regard to the following parameters: socket fit (72.9%), confidence/security (88.1%), gait and maneuverability (88.4%), physical attributes (65.8%), physical effects (61.5%), and negative attributes/limiting factors (85.3%). After use of the C-Leg, mean survey scores were significantly higher than initial responses associated with passive nonmicroprocessor controlled prosthetic knees (p Ͻ 0.0001). Conclusions: In comparison with their nonmicroprocessor controlled hydraulic prostheses, participants reported significant improvements with the C-Leg microprocessor controlled prosthetic knee with regard to comfort, security, maneuverability, cosmetic attributes, adverse effects, and safety.
Gait & Posture, 2007
Background: Microprocessor-controlled knee joints appeared on the market a decade ago. These joints are more sophisticated and more expensive than mechanical ones. The literature is contradictory regarding changes in gait and balance when using these sophisticated devices. Methods: This study employed a crossover design to assess the comparative performance of a passive mechanical knee prosthesis compared to a microprocessor-controlled knee joint in 15 subjects with an above-knee amputation. Objective measurements of gait and balance were obtained. Results: Subjects demonstrated significantly improved gait characteristics after receiving the microprocessor-controlled prosthetic knee joint (p < 0.01). Improvements in gait were a transition from a hyperextended knee to a flexed knee during loading response which resulted in a change from an internal knee flexor moment to a knee extensor moment. The participants' balance also improved (p < 0.01). All conditions of the Sensory Organization Test (SOT) demonstrated improvements in equilibrium score. The composite score also increased. Conclusions: Transfemoral amputees using a microprocessor-controlled knee have significant improvements in gait and balance.
Archives of Physical Medicine and Rehabilitation, 2007
Objective: To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies. Design: A-B-A-B reversal design. Setting: Home, community, and laboratory environments. Participants: Twenty-one unilateral, transfemoral amputees. Intervention: Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg). Main Outcome Measures: Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation. Results: Stair descent score, hill descent time, and hill sound-side step length showed significant (PϽ.01) improvement with the C-Leg. Users reported a significant (PϽ.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly (PϽ.001) greater than the mechanical control prosthesis. Conclusions: The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.
Prosthetics & Orthotics International, 2012
Background: Microprocessor controlled prosthetic knees (MPK) offer opportunities for improved walking stability and function, but some devices’ swing phase features may exceed needs of users with invariable cadence. One MPK offers computerized control of only stance (C-Leg Compact). Objective: To assess Medicare Functional Classification Level K2 walkers’ ramp negotiation performance, function and balance while using a non-MPK (NMPK) compared to the C-Leg Compact. Study Design: Crossover. Methods: Gait while ascending and descending a ramp (stride characteristics, kinematics, electromyography) and function were assessed in participant’s existing NMPK and again in the C-Leg Compact following accommodation. Results: Ramp ascent and descent were markedly faster in the C-Leg Compact compared to the NMPK ( p ≤ 0.006), owing to increases in stride length ( p ≤ 0.020) and cadence ( p ≤ 0.020). Residual limb peak knee flexion and ankle dorsiflexion were significantly greater (12.9° and 4.9°...
The Journal of Rehabilitation Research and Development, 2008
This study compared subjects' performance with a nonmicroprocessor knee mechanism (NMKM) versus a C-Leg on nine clinically repeatable evaluative measures. We recorded data on subjects' performance while they used an accommodated NMKM and, following a 90-day accommodation period, the C-Leg in a convenience sample of 19 transfemoral (TF) amputees (mean age 51 +/-19) from an outpatient prosthetic clinic. We found that use of the C-Leg improved function in all outcomes: (1) Prosthesis Evaluation Questionnaire scores increased 20% (p = 0.007), (2) stumbles decreased 59% (p = 0.006), (3) falls decreased 64% (p = 0.03), (4) 75 m selfselected walking speed on even terrain improved 15% (p = 0.03), (5) 75 m fastest possible walking speed (FPWS) on even terrain improved 12% (p = 0.005), (6) 38 m FPWS on uneven terrain improved 21% (p < 0.001), (7) 6 m FPWS on even terrain improved 17% (p = 0.001), (8) Montreal Rehabilitation Performance Profile Performance Composite Scores for stair descent increased for 12 subjects, and (9) the C-Leg was preferred over the NMKM by 14 subjects. Four limited community ambulators (Medicare Functional Classification Level [MFCL] K2) increased their ambulatory functional level to unlimited community ambulation (MFCL K3). Objective evaluative clinical measures are vital for justifying the medical necessity of knee mechanisms for TF amputees. Use of the C-Leg improves performance and quality of life and can increase MFCL and community ambulation level.
Prosthetics and Orthotics International, 2020
Background: Despite increasing knowledge about the potential benefits of advanced user-controlled technology, the decision about switching an individual prosthesis user from a non-microprocessor prosthetic knee to a microprocessor prosthetic knee is mainly based on clinician’s experience rather than empirical evidence. Objectives: To demonstrate the utility of single-subject design and data analysis for evaluating changes in temporal-spatial gait characteristics between walking with a non-microprocessor prosthetic knee and microprocessor prosthetic knee. Study design: Single-subject ABA/BAB design. Methods: Seven non-microprocessor prosthetic knee users (all men, age 50–84 years, 3–40 years post-amputation) were transitioned through the ABA or BAB phases (A-NMPK, B-MPK, 5 weeks each). Four weekly gait evaluations were performed at three self-selected speeds with an electronic walkway. The non-microprocessor prosthetic knee–microprocessor prosthetic knee differences in stride length–...
Journal of …, 2011
To assess the effects of using a microprocessorcontrolled prosthetic knee joint on the functional performance of activities of daily living in persons with an aboveknee leg amputation. Design: Randomised cross-over trial. Subjects: Forty-one persons with unilateral above-knee or knee disarticulation limb loss, classified as Medicare Functional Classification Level-2 (MFCL-2). Methods: Participants were measured in 3 conditions, i.e. using a mechanically controlled knee joint and two types of microprocessor-controlled prosthetic knee joints. Functional performance level was assessed using a test in which participants performed 17 simulated activities of daily living (Assessment of Daily Activity Performance in Transfemoral amputees test). Performance time was measured and selfperceived level of difficulty was scored on a visual analogue scale for each activity. Results: High levels of within-group variability in functional performance obscured detection of any effects of using a microprocessor-controlled prosthetic knee joint. Data analysis after stratification of the participants into 3 subgroups, i.e. participants with a "low", "intermediate" and "high" functional mobility level, showed that the two higher functional subgroups performed significantly faster using microprocessor-controlled prosthetic knee joints. Conclusion: MFCL-2 amputees constitute a heterogeneous patient group with large variation in functional performance levels. A substantial part of this group seems to benefit from using a microprocessor-controlled prosthetic knee joint when performing activities of daily living.
Physical Therapy, 2022
Objective People with transfemoral amputation have balance and mobility problems and are at high risk of falling. An adequate prosthetic prescription is essential to maximize their functional levels and enhance their quality of life. This study aimed to evaluate the degree of safety against falls offered by different prosthetic knees. Methods A retrospective study was conducted using data from a center for prosthetic fitting and rehabilitation. Eligible individuals were adults with unilateral transfemoral amputation or knee disarticulation. The prosthetic knee models were grouped into 4 categories: locked knees, articulating mechanical knees (AMKs), fluid-controlled knees (FK), and microprocessor-controlled knees (MPK). The outcome was the number of falls experienced during inpatient rehabilitation while wearing the prosthesis. Association analyses were performed with mixed-effect Poisson models. Propensity score weighting was used to adjust causal estimates for participant confound...