Objective Kyphosis is one of the common abnormalities of the spine. However, correct preservation of the posture can play an important role in preventing and treating kyphosis. Biofeedback systems are among the methods used to prevent postural dysfunction. This study aimed to design a biofeedback tool to prevent kyphosis and evaluated reliability and validity of this tool.
Materials & Methods total of 17 students aged between 18 and 30 years participated in the study as inappropriately. In this study, a flexible ruler was used as a golden standard to measure the kyphosis. First, a microcontroller-based kyphosis control biofeedback device was designed using a flexural sensor. This device consists of a vibration generator that activates when microcontroller detects a kyphotic situation. In other words, by changing the physical condition, the flexural sensor resistance used in the smart biofeedback tool changes accordingly and the data collected by the flexural sensor are converted into a voltage variation with a simple resistance circuit. The output of the flexural sensor is input to the microcontroller so that as soon as the microcontroller detects an incorrect physical condition, it sends a control signal (based on the predefined threshold for the microcontroller) in a vibration feedback. If the curvature value is more than the threshold and lasts for at least 30 seconds, it will alert the user with vibration feedback. Vibration alert continues as long as the user is in the kyphotic situation and stops as soon as the user leaves the kyphotic situation and returns to the natural state. After installing the designed biofeedback tool on the target area of the body, the tool error is evaluated by counting the number of warnings in the normal state and lack of warning in the kyphotic condition. In addition, to check the repeatability of the biofeedback tool, measurements were made in two neutral conditions and a tissue for each situation twice, with a distance of 2 hours. In this research, the tool validity was measured by Kappa coefficient based on sensitivity, specificity, and reliability. 
Results Correction of the physical condition is an effective technique used to reduce mechanical stress on the neck and shoulders by taking a natural state of the body. Wearable technology is a way to achieve this objective by continuously monitoring the physical condition of the person and giving him or her the needed feedback when the person’s physical condition deviates from normal condition. In this research, a wearable tool was designed that people can use it very easily. Therefore, it can be used as a useful, simple, and non-invasive tool for clinical evaluation and measurement of kyphotic postural information. With further development of data recordings and feedback mechanisms, this system can be transformed into a portable tracking and posturing system to educate patients with spine deviations. This system is an inexpensive user-friendly device.
The results showed that the sensitivity of the designed biofeedback tool was 17.64% and its property was 100%. The kappa index was calculated at 100% for both neutral states, but in the first one, 17.64% was measured in the first load and 12% in the second time. Regarding the repeatability of the biofeedback tool, the studies showed that the results of the first and second times did not differ significantly.
Conclusion To the results, the biofeedback tool has sufficient validity in the neutral state, but it was not sufficient in the paper situation . In other words, the designed biofeedback device does not correctly diagnose the physical condition of the body in accordance with the golden standard (flexible ruler). In this regard, further consideration should be given to address its deficiencies. In addition, Kappa index values showed that the biofeedback tool was not well-suited to the kyphotic condition. However, this tool has a great deal of reliability at the time.

Objective: The prevention of thumb joints flexion help cure de Quervain tenosynovitis. The thumb, therefore, is being immobilized in the abduction position by splinting. Thumb abduction can be away from the palm (palmar abduction) or from the fingers (radial abduction), which are done in two different planes. To the authors' knowledge, the literature has not specified which kind of thumb abduction has better treatment outcomes and functions. This study aimed to compare the immediate efficacy of palmar abduction and radial abduction splinting on the severity of pain, handgrip, palmar and lateral pinch strength, and hand function in people with de Quervain tenosynovitis.
Materials & Methods: In this quasi-experimental study, 30 volunteer patients (24 females) with de Quervain tenosynovitis referred to clinical centers were selected via convenience sampling. The participants were randomly assigned to three study groups (without the splint, palmar abduction splint, and radial abduction splint). The splints' height was two-thirds of the elbow. The splints were designed to immobilize the carpometacarpal and metacarpophalangeal joint of the thumb but allow the interphalangeal joint to move. One splint immobilizes the thumb in palmar abduction, while another immobilizes the thumb in radial abduction. The outcomes were studied and measured immediately after the intervention and in a single session. The intended outcomes included pain severity, handgrip strength, palmar and lateral pinch strength, and hand function measured with a visual analog scale, hand dynamometers, and the Jebsen-Taylor test, respectively. The repeated measures analysis of variance was performed for statistical analysis using SPSS software, version 16.
Results: All participants completed all study assessments. The results showed a significant reduction of pain, handgrip strength, lateral and palmar pinch, and hand function after using a thumb splint compared to without the splint condition (P<0.05). The pain severity in gripping objects was lower after using a palmar abduction splint than the radial abduction splint. Also, the strength reduction in taking objects by gripping, lateral pinch, and palmar was lower after using the palmar abduction splint than the radial abduction splint (P<0.05). Still, both splints were not significantly different in slowing the hand function in the Jebsen-Taylor test (P>0.05).
Conclusion: The positioning of the thumb in palmar abduction with splinting could be more effective for pain reduction and manipulation of objects with the hand and fingers.