Does thermoplastics' thickness influence joint stabilization and movement coordination? An inferential study of wrist orthoses.

BACKGROUND: Given the existence of multiple low-temperature thermoplastics, clinicians fabricating can readily modify an orthoses' thickness, weight and flexibility, among other properties. However, there is limited evidence on the impact of such different materials on upper extremities' biomechanics. OBJECTIVE: Our study aimed to investigate differences in joint stabilization and movement coordination provided by upper extremity orthotics fabricated with low-temperature thermoplastics of different thicknesses. STUDY DESIGN: Inferential, cross-sectional study. METHOD: We conducted a kinematic analysis of a standardized task through a three-dimensional motion capture system. Ten participants (5 female) performed the same task under three circumstances: 1) wearing a volar wrist immobilization orthosis, made with a 3.2-mm thick low-temperature thermoplastic; 2) using the same orthotic fabricated with a 1.6-mm thick material; and (3) without orthoses. We divided the standardized task into five logical phases for data analysis, obtaining the active range of motion of the shoulder, elbow, forearm, and wrist joints as the primary outcome. Secondary outcomes included movement smoothness and coordination, measured by the number of motor units, time, and distance travelled by the upper extremity. RESULTS: Despite changes in thermoplastic thickness, both orthotics significantly restricted the wrist motion during task performance (F(2,16) = 14.32, P < .01, and η2p = 0.797), with no difference between the 2 devices and no significant changes to proximal joints' active range of motion. Although orthoses use increased the time required for task performance (F(2,16) = 23.05, P < .01, and η2p = 0.742), no significant differences in movement smoothness or coordination were noted. CONCLUSION: Our results indicate that wrist orthoses fabricated with a 1.6-mm thick low-temperature thermoplastic can provide joint stabilization similar to a device made from a 3.2-mm thickness material, suggesting thinner thermoplastics' efficacy to stabilize joints in the absence of contractures or preexisting chronic conditions.

Orthotic use for CMC osteoarthritis: Variations among different health professionals in Brazil.

STUDY DESIGN: Cross-sectional descriptive study. INTRODUCTION: Osteoarthritis (OA) is the most prevalent musculoskeletal disease in the adult and older adult populations. The use of orthoses to stabilize the thumb's articular complex is one of the most common conservative management strategies. Despite substantial research about this topic, there is insufficient evidence about the optimal use of orthoses to inform clinical practice, contributing to practice variations within and across health professionals. PURPOSE OF THE STUDY: To identify the prescription patterns, design preferences, and barriers for the use of orthotic devices among Brazilian health care professionals involved in the treatment of patients with OA of the basal thumb joint. METHODS: An electronic questionnaire was sent to occupational therapists, physiotherapists, and rheumatologists across Brazil through professional association mailing lists. Survey included questions about orthosis design, materials, and barriers to the use of orthotic interventions. Respondents indicated their use based on photographs of 25 orthoses models that were selected through bibliographic review and expert consultation. Descriptive statistics, the chi-square test for independence, and the Fisher exact test were used to compare differences among orthotic prescription preferences, barriers, and challenges observed amidst the 3 participants' professional classes. RESULTS: There was no consensus about orthotic prescription among 275 professionals who answered the survey. About 69% of participants reported the use of multiple orthosis during treatment of patients with thumb OA. Results suggest significant variations in the number of joints included and stabilization strategies adopted, with a preference for orthotics made in rigid materials and involving the wrist, carpometacarpal, and metacarpophalangeal joints (P < .001). The lack of knowledge about orthotic options, institutional regulations, and policies were the major barriers reported by respondents (P < .01). CONCLUSION: A plentiful variety of different orthoses designs were observed in this study, and the prescriptions made by 3 professional classes showed differences regarding types of stabilization, joint involvement, and positioning. Despite the existence of clinical trials suggesting benefits for specific custom-made design models, our results indicated widespread clinical variation in practices and preferences. LEVEL OF EVIDENCE: Not applicable.