Stance-control Knee-ankle-foot Orthosis Research Articles

Safety, walking ability, and satisfaction outcomes of the NEURO TRONIC stance-control knee-ankle-foot orthosis (SCKAFO): A comparative evaluation to the E-MAG active SCKAFO.

Stance control knee-ankle-foot orthoses (SCKAFOs) ensure knee stability by locking during stance while allowing knee flexion during swing. Differences in function of the knee joints and building principles between devices may affect their effectiveness. To investigate the preliminary effectiveness of a NEURO TRONIC on safety outcomes, net energy cost (EC), and user experiences in individuals already using an E-MAG Active SCKAFO. Prospective uncontrolled intervention study. A convenience sample of 10 subjects with flaccid lower extremity muscle weakness, including the quadriceps, due to neuromuscular disorders already using an E-MAG Active SCKAFO were provided with a newly fabricated NEURO TRONIC SCKAFO. Outcomes included knee joint locking failures and unlocking failures (ULFs) (i.e., percentage of steps the knee joint failed to lock/unlock) when walking under challenging conditions on an instrumented treadmill while wearing a safety harness; net EC (J/kg per meter) assessed with a 6-min walk test at comfortable speed; 3D gait kinematics and kinetics; and patient-reported outcomes. No differences between devices were found for knee joint locking failures (both devices 0%) and ULFs (9.9% for the NEURO TRONIC vs. 13.9% for the E-MAG Active SCKAFO). The mean (standard deviation) net EC with the NEURO TRONIC SCKAFO was 8.2% (from 3.68 [0.81] to 3.38 [0.75] J/kg per meter, p = 0.123) lower, although not significantly, compared with that with the E-MAG Active SCKAFO. Significant improvements with the NEURO TRONIC SCKAFO were found for ankle power ( p = 0.003), perceived walking effort ( p = 0.014), and reported falls ( p = 0.034). Both the NEURO TRONIC SCKAFO and the E-MAG Active SCKAFO were safe in terms of knee joint locking, while ULFs were frequent with both devices. The net EC with the NEURO TRONIC SCKAFO decreased, although not significantly, by 8.2%, likely due to insufficient power. Perceived walking effort was in favor of the NEURO TRONIC SCKAFO.

Feasibility of a Powered Knee Joint in Providing Stance and Swing Phase Knee Flexion when Using a Knee-Ankle-Foot Orthosis

ABSTRACT Background The aim of this study was to develop a new stance control knee-ankle-foot orthosis (SCKAFO) and determine its efficacy on specific spatiotemporal and kinematic parameters. Method Seven healthy volunteer subjects participated in this study. After orthotic gait training, subjects participated in a four-part data collection session that consisted of gait evaluation with normal walking, SCKAFO with locked knee joint, SCKAFO without initial flexion (IF) mode, and SCKAFO with IF mode. Results Walking with any of the control knee-ankle-foot orthoses (KAFOs) produced a significant reduction in walking speed compared with normal walking. There was no significant difference in walking speed between the SCKAFO with and without IF. There was significantly higher knee flexion in stance phase when walking with the SCKAFO with IF compared with the other types of KAFO, but there was no significant difference between normal walking and SCKAFO with IF. In wearing SCKAFO with IF, the mean of the hip flexion was not significantly altered compared with normal walking. Hip abduction was also significantly reduced during walking with stance control (SC) mode compared to KAFO with locked knee joint. Conclusion Knee-ankle-foot orthosis with new powered knee joint has benefits over existing assistive KAFOs with locked and SC knee joints.

The effect of 'Sensor Lock', a knee–ankle–foot orthosis with an electromechanical stance control knee joint, on walking parameters and gait symmetry of subjects with quadriceps weakness: a pilot study

Pilot study. This study aimed to evaluate an electromechanical stance control (SC) knee joint, 'sensor lock', which could potentially solve the problems of walking parameters and gait symmetry in subjects with poliomyelitis. University of Social Welfare and Rehabilitation Sciences. Six subjects with quadriceps weakness were enrolled in this study. A custom-made stance-control knee–ankle–foot orthosis (SCKAFO) with the same set of components was constructed for each participant. A motion analysis system was used for analysis of lower limb kinematics. There were no significant differences between the knee–ankle–foot orthoses (KAFOs) and the two types of knee joints with regard to temporal–spatial parameters. Walking speed and cadence reduced and stride length increased in the stance control (SC) mode compared to the knee joint locked mode. The maximum knee flexion angle during swing phase increased when walking with SC mode compared to walking with the KAFO in knee joint lock mode. There was a significant difference between two test conditions with regard to hip flexion. There were only significant differences in the symmetry index of the knee flexion between two test conditions. Compared to locked knee mode, SC mode demonstrated a slower speed of walking and increased peak knee flexion during swing. Regarding gait symmetry, the symmetry index of the knee flexion and speed of walking decreased when the KAFO with SC mode was used compared to KAFO with knee joint locked mode.

Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis.

A 54-year-old man with poliomyelitis had been using a conventional, passive knee-ankle-foot orthosis (KAFO) with a drop ring lock knee joint for about 40 years. A stance control KAFO (SCKAFO) with an electromagnetically controlled (E-MAG) knee joint system was prescribed. To correct his gait pattern, he also underwent rehabilitation therapy, which included muscle re-education, neuromuscular electrical stimulation, strengthening exercises for the lower extremities, and balance training twice a week for about 4 months. Both before and after rehabilitation, we conducted a gait analysis and assessed the physiological cost index in energy expended during walking in a locked-knee state and while he wore a SCKAFO with E-MAG. When compared with the pre-rehabilitation data, the velocity, step length, stride length, and knee kinematic data were improved after rehabilitation. Although the SCKAFO with E-MAG system facilitated the control of knee motion during ambulation, appropriate rehabilitative therapy was also needed to achieve a normal gait pattern.

Design and Evaluation of a Stance-Control Knee-Ankle-Foot Orthosis Knee Joint

Conventional knee-ankle-foot orthoses (KAFOs) are prescribed for people with knee-extensor muscle weakness. However, the orthoses lock the knee in full extension and, therefore, do not permit a natural gait pattern. A new electromechanical stance-control knee-ankle-foot orthosis (SCKAFO) knee joint that employs a novel friction-based belt-clamping mechanism was designed to enable a more natural gait. The SCKAFO knee joint allows free knee motion during swing and other non-weight-bearing activities and inhibits knee flexion while allowing knee extension during weight bearing. A prototype SCKAFO knee joint was mechanically tested to determine the moment at failure, loading behavior, and wear resistance. The mean maximum resisting moment of the SCKAFO knee joint over five loading trials was 69 Nm +/- 4.9 Nm. The SCKAFO knee-joint strength and performance were sufficient to allow testing on a 90 kg subject at normal walking cadence. Proper function of the new electromechanical knee joint was verified in walking trials of an able-bodied subject.

Gait Evaluation of an Automatic Stance-Control Knee Orthosis in a Patient With Postpoliomyelitis

Hebert JS, Liggins AB. Gait evaluation of an automatic stance-control knee orthosis in a patient with postpoliomyelitis. Objective To determine gait differences in a subject ambulating with a knee-ankle-foot orthosis (KAFO) with a locked knee joint versus an automatic stance-control knee joint. Design Single-subject crossover design. Setting Tertiary rehabilitation facility with a motion analysis laboratory. Participant A 61-year-old ambulatory male volunteer with postpoliomyelitis walking with a stance-control KAFO. Interventions Instrumented gait analysis and Physiological Cost Index in the locked knee and stance-control modes. Main Outcome Measure Differences in gait parameters. Results On the braced limb, stance-control mode showed a near-normal knee flexion wave in swing, reduced pelvic retraction and rotational excursion, and improved hip power generation. On the nonbraced limb, the stance-control mode allowed elimination of vaulting, reduction in abnormal ankle and hip power generation, increased knee power absorption, and more typical quadriceps activation. There was a trend toward improved energy efficiency in the stance-control mode. Conclusions Use of a stance-control knee joint in a KAFO appears to improve gait biomechanics and improve energy efficiency compared with a locked knee.