Strap System Research Articles

“A ‘One-piece’ gutter orthosis/strapping alternative”

Patients often have difficulty securing and positioning finger orthoses (splints). Using standard strapping materials molded directly into the orthotic device, this author describes an alternative strapping system for these small finger orthoses. —Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor

Nonlaminated FRP Strap Elements for Reinforced Concrete, Timber, and Masonry Applications

Advances in material technology allow for the exploration of new structural forms and systems. In recent years, fiber-reinforced polymers (FRPs) have emerged as candidate materials for civil engineering applications, and the use of FRPs in construction has been an area of growing interest. Unidirectional high-strength FRPs are well-suited for use as tensioning elements, but anchorage details present a challenge. An alternative is to self-anchor the FRP tensioning element by winding thin layers of material around supports and then laminating all the layers together (a laminated strap) or by securing only the outermost layer to form a closed outer loop while the inner layers remain nonlaminated (a nonlaminated strap). Nonlaminated FRP straps have been found to have higher efficiencies than equivalent laminated straps, which is advantageous in high-tension applications. The suitability of nonlaminated FRP straps for use as unbonded tension elements provides scope for use in new construction and for the strengthening of existing structures. A review of nonlaminated carbon FRP strap system properties and applications in the context of reinforced concrete, timber, and masonry structures is presented.

Ankle Brace with a Calcaneal Strapping System Alters COP Displacement During Gait

A recent study examined the effectiveness of semi-rigid ankle brace (Element) with an elastic calcaneal strapping system in controlling heel inversion in healthy subjects. To date, no studies have documented the effects of a similar ankle brace on the ankle mechanics in populations with chronic ankle instability (CAI). PURPOSE: To examine the effect of a shorter version of the same semi-rigid ankle brace with the calcaneal strapping system designed for sport on displacement of center of pressure (COP) during gait and landing in participants with CAI. METHODS: The Ankle Joint Functional Assessment Tool (AJFAT) was used to identify 10 healthy subjects (mean AJFAT score 26.7 ± 1.1) and 10 subjects with CAI (mean AJFAT score 14.9 ± 5.5). Participants performed five trials in each of the nine testing conditions: level walking at 1.2 m/s, running at 3.6 m/s, drop landing from an over-head bar from a height of 0.6 m, wearing no brace, the semi-rigid brace (Element), and a soft lace-up brace (ASO). Simultaneous recording of 3D kinematic (240 Hz) and ground reaction force (2400 Hz) data were performed. Kinematic and kinetic variables were computed using Visual 3D (C-Motion, Inc). A 2 × 3 (group × brace) mixed design ANOVA was used detect the group and brace differences for the COP variable (p < 0.05). RESULTS: The result showed a significant brace effect on the medial-lateral COP range during walking (F = 13.172, p < 0.001) but no group difference or interaction was found. The post hoc comparisons demonstrated that Element had significantly less medial COP movement compared to no brace and ASO. There was a marginal decrease in the medial COP movement in Element compared to no brace (p = 0.066) during running. No differences were found among the brace conditions in drop landing. CONCLUSION: These changes in the COP displacement during gait appear to be due to a more medial starting position at heel strike, which may be related to the limitation of Element brace and a more neutral calcaneal initial position due to the application of the strap. During running and landing, the increased loading to the body and foot as a result of increased gait or vertical speed seem to reduce the effects of the brace. Ankle instability does not alter the effects of ankle braces on COP movements. Supported by DeRoyal Industries, Inc.

Prosthetic strap system for simplified ventral hernia repair: results of a porcine experimental model

Aiming to achieve a simplified ventral hernia repair, a proprietary oval-shaped mesh was experimentally tested in a porcine model. The mesh is structured with a large central body and radiating straps. The friction of the straps passing through the tissues are hypothesized to be adequate to maintain the position of the mesh during tissue ingrowth, avoiding classic point fixation while ensuring a wide coverage of the abdomen. The mesh, having six radial straps, was placed using a sublay preperitoneal technique in four pigs. All straps were passed laterally through the abdominal wall and exteriorized from the skin. The straps were trimmed at the level of the skin, allowing the stumps to recoil into the subcutaneous space. The animals were euthanized at 1 and 4 months to determine the integration of the straps. Macroscopically, all 24 straps were firmly incorporated within the abdominal wall. The tension-free placement of the mesh by using the straps was effective. The friction of the straps passing through the tissues was adequate to keep the mesh well orientated. No dislocation of the implants was observed. The strap system also allowed a broader coverage of the abdominal wall, far beyond the wound opening. The described arm system of the aforementioned implant seems to be effective in eliminating point fixation of the mesh. The fixation arms seemed to have ensured that the mesh stayed orientated in all of the animals. A very wide lateral mesh placement was accomplished, assuring sufficient defect overlap when shrinkage occurs.

Evaluation of intra-fraction patient movement for the head & neck IMRT

Purpose/Objective: Patients often have more chances to move during IMRT delivery compared to conventional radiation therapy primarily due to longer treatment time. It is impossible to totally eliminate patient movement. Therefore, it is important to quantify patient movement for each specific clinical situation and appropriately account for it in planning margin. The goal of this study is to quantify the intra-fraction movement of patients during the head and neck IMRT. We have developed a novel concept of cumulative time versus patient positioning uncertainty histogram (TUH) that has allowed us to establish adequate margins for intra-fraction patient movement. Materials/Methods: The movement of head & neck IMRT patient was monitored using a commercial camera monitoring system (ExacTrac; BrainLab). The infrared markers seen by this camera system were rigidly placed on a custom bite-frame that was fabricated for each patient. All patients were immobilized using a Vac Fix mold and strap system. Patient movement was monitored and recorded every 2 seconds during the IMRT treatment. Prior to the initiation of this study, we also evaluated the effectiveness of immobilization of Vac Fix mold with straps with non-patient subjects. We found that the maximum/mean displacements for non-patient subjects were 1.29/0.75 mm. Based on this result; we conservatively set 2 mm tolerance for intra-fraction patient movement. Results: Intra-fraction patient movement data for 4 patients acquired for 20 fractions showed that all patients have a general tendency to move as the treatment progresses in time. We plotted the patient movement uncertainty as a function of cumulated treatment time (TUH) from 1, 2, 3, 4, 5, 10, 15, and 20 treatment fractions. Figure 1 shows that the TUH for an IMRT patient treatment has a distinct sigmoid shape. We define a quantity, U(x,y) as uncertainty that will assure target coverage for × % of treatment time through Y treatment fractions. For example, U(95,20) is 0.88 mm in Fig 1. TUH indicates that U(95,y) is more meaningful as uncertainty because it is close to where the high uncertainty shoulder on the curve begins. We obtained U(95,20) values of 1.24, 0.88, 1.22, and 1.75 mm in 20 fractions for 4 patients. All were within 2 mm of tolerance. Data shows that U(95,5) can also be used for patient specific uncertainty in re-planning without a significant loss of accuracy. Differences between U(95,5) and U(95,20) were less than .15 mm for 4 patients. Conclusions: New quantities, TUH and U(x,y) are useful in the interpretation of intra-faction uncertainty and are ideally suited for adaptive radiation therapy.

Opening doors with assistive technology.

Results of the 2001 RESNA student scientific paper and student design competitions are presented. The topics dealt with included: scapula orientation in a virtual wheelchair push; repeatability of determining effective Young's modulus of buttocks soft tissue across multiple subjects; power and control system testing of five different types of power wheelchairs; modification of hybrid III test dummy for use in wheelchair studies; effect of adult-onset diabetes and/or peripheral neuropathy on acceleration threshold detection during horizontal translations; battery tester for people with physical and mental disabilities; design of a modular sensory feedback system to enhance physical education of persons with disabilities; an assistive technology key turning device for independent entryway access; ear-chin strap system for sleep apnea.

Adaptation and verification of the relocatable gill-thomas-cosman frame in stereotactic radiotherapy

Purpose : Stereotactic radiotherapy (SRT) combines techniques of stereotactic radiosurgery (SRS) with radiation therapy fractionation schemes. Fractionation in SRT necessitates a relocatable immobilization system to precisely reproduce the patient's position at each treatment. The Gill-Thomas-Cosman (GTC) head frame is such an immobilization device compatible with the Brown-Roberts-Wells (BRW) stereotactic system. We describe this device, our modifications to the original design, the repeat position accuracy, and the daily verification procedure. Methods and Materials : The original GTC frame was tested on volunteers. This testing led to an improved strapping system, the decision to construct the oral fixation appliance at our dental clinic, and the construction of a depth confirmation helmet to rapidly confirm the position of the frame on a daily basis. The GTC frame, at our institution, is not acceptable for children requiring anesthesia, and a new frame, the “Boston Childrens' Hospital” frame, was designed. This device uses the base ring of the GTC frame. Airway access is maintained through fixation on the nasal-glabellar region and the ear canal rather than the hard palate and upper gingiva. Results : The modifications of the GTC frame and the verification protocol result in repeat positioning of the frame with respect to the patient anatomy, with a standard deviation of 0.4 mm for both the modified GTC frame and the Boston Childrens' Hospital frame. The relocatibility of the frames has been established in over 2,000 patient setups in over 60 patients to date. Discussion : The GTC frame is a noninvasive and versatile fixation system that provides patient comfort, as well as accurate relocatibility for SRT. The frame is not appropriate for single fraction radiosurgery, as a large setup error (> 2 mm) for a single treatment cannot be excluded. The GTC frame is compatible with the BRW system, and treatment planning for SRT and SRS patients is identical. We currently treat 10–13 SRT patients per day with intracranial neoplasms on a dedicated stereotactic therapy unit. In addition, the Boston Childrens' Hospital frame allows the use of stereotactic therapy in the treatment of children under 6 years of age. This population will benefit especially from precise and highly focal cranial irradiation.

Effects of Pelvic and Lower Extremity Stabilization on Isometric Trunk Extension and Flexion Muscle Strength

The purpose of this study was to evaluate the effect of varying the type of pelvic and lower extremity stabilization on isometric trunk extension and flexion muscle strength measurements. Two pelvic stabilization systems, one consisting of fixation of the anterior superior iliac spines and sacrum (pelvic fixation) and the second, a strap across the anterior superior iliac spines and a posterior pad at the sacrum (pelvic strap) were compared. The lower extremities were or were not strapped at the thigh, calf, and feet. Torque values for the pelvic fixation system were not different from the pelvic strap system with lower extremity stabilization. Torque values were less with no lower extremity stabilization with both pelvic stabilization systems for flexion but not for extension muscle contractions. The use of an extensive pelvic stabilization system did not produce greater isometric force output than the use of a simple pelvic strap. The use of lower extremity stabilization did produce greater isometric flexion force output than the use of no lower extremity stabilization. J Ortho Sports Phys Ther 1987;9(3):111-117.

A COMFORTABLE ARRANGEMENT FOR THE SEPARATE COLLECTION OF URINE AND FECES OF MALE INFANTS

Of the utmost importance in the quantitative investigation of infant excretions is the absolutely complete collection of the separate urine and feces for the desired period. Hardly second in importance is the question of comfort for the child, for it is possible that a constrained or unusual posture appreciably affects the metabolism. For example, one arrangement, in which the body is partly supported as in a hammock, brings considerable pressure on the lower part of the back and in some cases has seemed to cause increased peristalsis. With another method the bed is necessarily slightly tilted and the child held from slipping by an elaborate system of straps so arranged as not to press on any part of the body but holding shoulders and arms in an almost immovable position. The arrangement here described is recommended as combining accuracy of collection with a maximum of comfort for the child. It