Studies on Argentinean species of the Bahitini leafhopper genus Menosoma Ball, 1931 (Hemiptera: Cicadellidae); checklist, key to known species, and redescription of Menosoma taeniatum Linnavuori with a new country record.

The species of the genus Menosoma to occur in Argentina are revised. Menosoma taeniatum Linnavuori is redescribed using recent samples taken from Northeast Argentina. Overall habitus images of external and internal morphology are provided. In addition, a new country record is reported for Bolivia. An updated checklist and key to all Menosoma species known to occur in Argentina are also given.

A new species of the grass-feeding leafhopper genus Amblysellus Sleesman (Hemiptera: Cicadellidae: Deltocephalinae) from western Mexico, with a checklist and key to species.

A new Mexican leafhopper species, Amblysellus raygozai sp. nov., is described and illustrated from western Mexico. Specimens were collected over perennial grasses. A key for all recognized species within the country is provided.

Assessment of the postural control strategies used to play two Wii Fit™ videogames.

The Nintendo Wii Fit™ may provide an affordable alternative to traditional biofeedback or virtual reality systems for retraining or improving motor function in populations with impaired balance. The purpose of this study was to evaluate postural control strategies healthy individuals use to play Wii Fit™ videogames. Sixteen young adults played 10 trials of Ski Slalom and Soccer Heading respectively. Centre of pressure (COP) excursion and three-dimensional movement data were acquired to determine variability in medial-lateral COP sway and shoulder-pelvic movement. While there was no difference in medial-lateral COP variability between games during trial 1, there was a significant difference after 10 trials. COP sway increased (59-75 mm) for Soccer Heading while it decreased (67-33 mm) for Ski Slalom from trial 1 to trial 10. During Ski Slalom participants demonstrated decreased shoulder and pelvic movement combined with increased pelvic-shoulder coupling. Conversely, participants demonstrated greater initial shoulder tilt when playing Soccer Heading, with no reduction in pelvic rotation and tilt. Participants decreased pelvic and trunk movements when skiing, suggesting a greater contribution of lower extremity control while they primarily used a trunk strategy to play Soccer Heading.

Joint excursion, handle velocity, and applied force: a biomechanical analysis of ergonometric rowing.

Rowers may sacrifice on-water technique during ergonometric training in an attempt to increase stroke output. This cross-sectional study aimed to identify characteristics of ergonometric rowing technique that could be potentially detrimental to an effective and safe on-water performance. Joint excursion, handle velocity, and applied force were measured in 44 athletes while they performed a 2500 meter race on an instrumented ergometer. Results on four subjects are presented here. Their performance is compared to that of a Barcelona Olympic and World champion rower with 12 years of experience to illustrate how athletes deviate from standard on-water technique. Kinematic data showed knee joint oscillations and out-of-phase hip and knee joint reversals. Horizontal handle velocity curves indicated that higher stroke rates were achieved by a decrease in recovery time. Vertical handle velocity curves exhibited bi-directional variations. The largest amplitude occurred at the end of the drive phase during an upward displacement of the handle that was associated with a jerk in the applied force. Force-time curves at different stroke rates showed greater variability in the initial portion of the drive phase. Perpetuation of these technique deviations may be detrimental to on-water performance. Biomechanical analyses may allow coaches to better monitor technique during ergonometric training.

Analysis of assisted-gait characteristics in persons with incomplete spinal cord injury.

UNLABELLED: Ambulatory assistive device use can improve functional independence following spinal cord injury and, potentially, quality of life. However, the interaction between aids and user in this population is poorly understood. OBJECTIVES: To determine the influence of walkers, crutches and canes on assisted-gait following incomplete spinal cord injury. STUDY DESIGN/METHODS: Outcome parameters evaluated in ten individuals included orthogonal forces exerted on instrumented assistive devices, walking speed, cadence, step length, trunk and thigh angles, as well as knee and ankle joint angles. Kinetic data included axial compressive force, and medio/lateral and antero/posterior bending forces. SETTING: Canada. RESULTS: Results indicated that walkers (n= 5) provided the greatest vertical support (up to 100% body weight), but resulted in slow gait with a forward flexed posture. Elbow crutch users (n = 3) walked faster (greater step length and cadence) and had a more upright posture than the walker users. Crutches supported up to 50% of the subject's body weight, granted lateral stability, and provided restraint in the antero/posterior direction. Canes (n = 2) offered restraining and propulsive assistance, some lateral stability, and the least amount of vertical support. CONCLUSION: Ambulatory devices affected posture and walking speed while fulfilling various assistive functions during locomotion. The conclusion drawn is that rehabilitation specialists are advised to match device characteristics to user needs when prescribing walking aids. SPONSORSHIP: Natural Sciences and Engineering Research Council of Canada (NSERC).

A computer-aided socket design procedure for above-knee prostheses.

A computer-aided socket design procedure (CASD) has been developed whereby an above-knee socket shape can be created based on anthropometric measurements taken from an amputee. The anthroometric measurements are used to select a subset of three reference shapes from a Reference Shape Library stored in the computer in the form of three-dimensional numerical data. Transformation procedures then scale the reference shapes at each cross-sectional level to match the amputee's cross-sectional areas. Blending of the three shapes is determined by tissue mass weighting factors, to yield a single custom socket configuration, known as the "basic socket shape." Subsequent graphical procedures in the CASD system allows further sculpting of the shape in the form of interactive adjustments of the numerical data to reach the socket shape desired by the prosthetist. The resultant shape data can then be transferred to a computer numerically controlled (CNC) milling machine to carve a model of the socket shape.

Computer-aided design and manufacture of an above-knee amputee socket.

This paper describes the initial test results obtained from a newly developed computer-aided socket design (CASD) and manufacturing (CASM) process for above-knee amputees. Anthropometric measures taken from an amputee provided input information to a CASD system. Using these measurements, data from a reference shape library stored in the computer were selected and modified to create a unique socket shape reflecting the particular characteristics of the amputation stump. The resultant shape was produced as a 'primitive' test socket by a CASM process. Numerical shape data were then transferred to a CNC milling machine to construct a negative cast, from which the primitive socket was produced by a vacuum-forming procedure. The resultant primitive socket shape was fitted and the amputee was able to load the socket without discomfort. Some shape discrepancies were identified and the shape data were modified interactively by the CASD system to create a final socket shape. The final socket shape was manufactured and worn by the amputee during a 35 min walking trial. Subjective evaluation was that the socket provided comfort and control comparable with that of the conventional socket, and proved to be acceptable to the amputee. This was followed by a 2-month home trial which was also successful. The CASD socket shapes were compared numerically in area, shape and volume with data taken from the original socket worn by the amputee, a new socket made by conventional methods and a topographic model of the amputation stump. The final CASD socket shape compared favourably with that of a socket manufactured by conventional methods.(ABSTRACT TRUNCATED AT 250 WORDS)

A reference shape library for computer aided socket design in above-knee prostheses.

A Reference Library of socket shapes for an Above-Knee Computer Aided Socket Design (CASD) System has been created. This library forms part of a more general CASD System (Dean & Saunders, 1985; Novicov & Foort, 1982). It consists of a matrix of reference shapes representing above-knee socket characteristics and is based upon skeletal structure, residuum length and tissue mass. A set of 27 biomechanical reference shapes in the form of male plaster casts were produced by a combination of CNC milling and traditional artisan techniques. Each reference shape was digitized to obtain its cylindrical coordinates. Cross-sectional areas and tissue distributions within each shape and between the shapes were analyzed, modified and then stored numerically within the computer for further implementation of the CASD System for the above-knee amputees. The creation and the analysis of the reference shape data is described.