A haptic feedback system has been developed to provide sensory information to patients with lower-limb prostheses or peripheral neuropathy. Piezoresistive force sensors were mounted against four critical contact points of the foot to collect and relay force information to a system controller, which in turn drives four corresponding pneumatically controlled balloon actuators. The silicone-based balloon actuators were mounted on a cuff worn on the middle thigh, with skin contacts on the posterior, anterior, medial, and lateral surfaces of the thigh. Actuator characterization and human perceptual testing were performed to determine the effectiveness of the system in providing tactile stimuli. The actuators were determined to have a monotonic input pressure-vertical deflection response. Six normal subjects wearing the actuator cuff were able to differentiate inflation patterns, directional stimuli and discriminate between three force levels with 99.0%, 94.8%, and 94.4% accuracy, respectively. With force sensors attached to a shoe insole worn by an operator, subjects were able to correctly indicate the movements of the operator with 95.8% accuracy. These results suggest that the pneumatic haptic feedback system design is a viable method to provide sensory feedback for the lower limbs.

A Haptic Feedback System for Lower-Limb Prostheses

Foot pressure measurement: A review of clinical findings

New disability testing and evaluation software combined with an isometric strength testing machine provides a very complete and standardized means of determining disability in comparison with the norms of the general population. The software utilizes not only the machine but also the digitization of photographs taken of the subject person during each strength test. Combining the digitized photographic data, the force monitor information from the load cell of the machine and extensive anthropomorphic data the software calculates for loading of the weakest joint in the subject person and compares this loading to normative values from the general population. In this manner a percentage disability for a subject person can be calculated with reasonable assurance of the validity and reproducibility of the result. New specialized hand grips for an isometric strength testing machine are disclosed to test grip strength and torsional strength of the hand.

Isometric strength testing method and equipment for disability evaluation

A study of normal locomotion requires an understanding of both the movements and the force actions involved. This is equally true in appreciating the problems of pathological gait.The gait cycle is described in terms of the significant events which occur during both the stance and swing phases.The basic principles underlying the analysis of force actions in walking are briefly described. A simple example of force actions in the elbow joint is considered and the analysis extrapolated to provide a general statement regarding locomotion. This relates to the muscle actions required to resist turning actions at joints due to the force effects in walking and the corresponding forces in the joints themselves.The conventional display of information relating to joint actions is considered and compared with the actual situation. “Stick diagrams” of motion in the sagittal plane are used to identify and discuss the actions at the joints of the leg in walking. Comparisons are made between this and pathological gait—in...

https://journals.sagepub.com/doi/pdf/10.3109/03093647909164693

Normal human locomotion.

Gait analysis using a measuring walkway for temporal and distance factors.

Only a few methods have been reported in the recent literature for measuring the forces under human feet in normal and abnormal cases The purpose of the present investigation was to study whether the static weight distribution under feet on the parafrontal plane can be used as a measure of lower extremity disability by using a system of load cells as transducers Three postpolio cases, three lower extremity amputees and three Perthes disease victims constituted the test group and five normal healthy adult males with sedentary habits formed the control group in this preliminary study Normalised weight distribution under the right and left foot of each test group subject has been compared with the mean and sd of the control group The test group subjects showed different degrees of variation from the control group in the static-weight-distribution pattern according to their disability

P. Mukherjee

Papers

Preliminary study on static weight distribution under the human foot as a measure of lower extremity disability.

A gait recording technique suitable for clinical use.

Detection of gait abnormality from tachographic data.

Preliminary observations on normal and rehabilitee cadence.

A digital gait recording technique