Elaine Ewing Fess

A method for checking Jamar dynamometer calibration

Abstract When calibrated correctly, the Jamar dynamometer is a highly reliable assessment instrument. Utilizing an adjustable-top workbench, positioning blocks, force collar, standardized test weights, and a careful testing procedure, the ability of a Jamar dynamometer to measure accurately and consistently may be evaluated. Resulting data may be plotted on graph paper for a general estimate of measurement capacity, whereas calculation of the correlation coefficient, mean of the standard weight applied, and mean of the dynamometer readings provide a more exacting assessment of instrument capacity. Dynamometers with a correlation coefficient of 0.9994 or better and a difference between the means of 1.5 pounds (0.68 kg) or less do not need recalibration. If the correlation coefficient is acceptable but the difference between the means is more than 1.5 pounds, the dynamometer may be adjusted by the calibration screw on the face plate. When the correlation coefficient is less than 0.9994, the instrument must be returned to the manufacturer for recalibration.

The Influence of Splinting on Healing Tissues

In addition to immobilizing injured soft tissue to allow healing, splints are used to positively influence collagen remodeling through the application of low-load forces to healing or contracted soft tissue, permitting soft tissue growth and concomitant increased function. When correction of limited passive range of motion due to soft tissue contracture is needed, splinting is an absolute requisite. No other currently available modality is able to hold a constant low-load tension for a prolonged time sufficient to cause tissue growth.

Splints: mechanics versus convention.

Splints are specialized engineering machines that are created to solve specific upper-extremity problems. Astute manipulation of mechanical concepts increases splint efficiency, enhances patient comfort and function, and improves splint durability, while diminishing cost and frustration. Creation of splint designs should be based on mechanical fact rather than on mode-of-the-day bias. Those who are responsible for the treatment of upper-extremity dysfunction and use splinting as a treatment modality must have a thorough working understanding of the engineering concepts involved. Splinting is both science and art but the ultimate criterium is does it work mechanically? If a splint does not work mechanically, then there is no reason for its application. The insight provided by understanding engineering concepts opens new horizons in patient treatment for those who take the time to learn.

Maintained Hand Function and Forearm Bone Health 14 Months After an In-Home Virtual-Reality Videogame Hand Telerehabilitation Intervention in an Adolescent With Hemiplegic Cerebral Palsy

Virtual reality videogames can be used to motivate rehabilitation, and telerehabilitation can be used to improve access to rehabilitation. These uses of technology to improve health outcomes are a burgeoning area of rehabilitation research. So far, there is a lack of reports of long-term outcomes of these types of interventions. The authors report a 15-year-old boy with hemiplegic cerebral palsy and epilepsy because of presumed perinatal stroke who improved his plegic hand function and increased his plegic forearm bone health during a 14-month virtual reality videogame hand telerehabilitation intervention. A total of 14 months after the intervention ended, repeat evaluation demonstrated maintenance of both increased hand function and forearm bone health. The implications of this work for the future of rehabilitation in children with neurological disabilities are discussed in this article.

Force magnitude of commercial spring-coil and spring-wire splints designed to extend the proximal interphalangeal joint

Abstract Forty commercial spring coil and spring wire splints were analyzed for production of force magnitude at differing degrees of flexion deformity. It was found that none of the splints tested generated the same force throughout the 10°–80° span of flexion angles. Instead, a progressive increase in force was noted for all splints as the flexion deformities increased. Inter-splint reliability was found to be most consistent in the “B” Capener and extension spring groups. Conversion of forces to torque permitted the means of the four groups to be compared. Unaltered “A” Capener splints and extension-assist splints were found to have extremely limited useful ranges when compared to safe torque parameters, culminating in 1915 cm gm and 2131 cm gm, respectively, for an 80° flexion deformity. “B” Capener and extension springs exhibited somewhat wider useful ranges. Torque generated by these types of splints may be lessened by bending the lateral distal wires into flexion, by shortening the distal aspect of the splint, and by lessening the tension on the distal straps (Capener design only).

Reliability of the Manual Dynamic Mode of the Baltimore Therapeutic Equipment Work Simulator

Twelve Baltimore Therapeutic Equipment Work Simulators (BTEWS) were tested for consistency of resistance in the manual dynamic mode using a previously described timed weight-drop test. Fifty weight-drop measurements were made at five different weight levels: 5, 10, 20, 30, and 40 lb. Alterations in weight-drop times indicate changes in exercise-head resistance. Substantial resistance variation was found in the manual dynamic mode. With console resistance set consistently at 92% of applied weight, weight-drop times varied from failures of the weight to drop to times that were not recognized by the electronic timing system. Measurable weight-drop times ranged from 0.75 to 16.97 seconds. Ten Simulators had weight-drop times greater than +/-3 standard deviations (SD) from the mean; eight Simulators had times +/-4 SD from the mean; and four had times +/-5 SD from the mean. Console printout data did not accurately reflect resistance produced by the exercise head. While intermachine correlations based on Simulator printout data ranged from +1.0 to +0.9906, correlations derived from resistance-based weight-drop times ranged from +0.9866 to -0.9956. For a constant externally applied torque, the weight-drop times should have been constant but were not. Resistance produced in the manual dynamic mode is inconsistent, both within and between machines (p = 0.0001).

Biomechanics: The Forces of Change and the Basis for All That We Do

Correspondence to Judith A. Bell-Krotoski, OTR, FAOTA, CHT; CAPT, U.S. Public Health Service, Chief, Hand and Occupational Therapy Department, Clinical Research Therapist, Gillis W. Long Hansens Disease Center, 5445 Point Clair Road, Carville, LA 707219607; or Elaine Ewing Fess, MS, OTR, FAOTA, CHT, Hand Research, 635 Eagle Creek Court, Zionsville, IN 46077. has both strength and preCISIon, in a smoothly orchestrated, versatile, and flexible system. Often our lifeline to the world, the hand responds quickly without thought, protecting the body from harm in a myriad of reflexes and patterns programmed in the brain. Its touch imprints the mind, as it becomes our interface for thoughts, dreams, and ideas, transferring them into creative action. It expresses our anger, our love, and our prayers, and is part of the beauty at the heart of the human soul, an outward sign of our inner being, gesturing without speaking, extending friendship, and, when needed, becoming an alternate language. Not fully appreciated until there

Convergence points of normal fingers in individual flexion and simultaneous flexion

The purpose of this study was to determine the point of convergence of normal fingers as they are flexed (1) individually and (2) simultaneously with the wrist in neutral, 30° extension, and 30° flexion. Eighty adult hands were evaluated using metal probes attached to the fingers to determine convergence point(s) of the flexed digits. Consistent attitude of the extremities tested was insured through positioning splints. Results indicate that 100% of the subjects demonstrated marked differences between convergence points for individual and simultaneous finger flexion (P < 00006). Individual finger convergence occurred most frequently in areas 15, 66, and 71, while simultaneous finger convergence occurred in areas 72, 73, and 74. Convergence patterns included four, three, or two digits, and both the index and small fingers exhibited marked deviation away from the midline of the hand upon simultaneous finger flexion (P < 00006). Having direct bearing on splinting and exercise concepts, this study indicates that the traditional idea of a single constant point of longitudinal convergence of the fingers in flexion is vastly oversimplified.