Evaluation of a Functional Brace in ACL-Deficient Subjects Measuring Ground Reaction Forces and Contact Pressure: A Pilot Study

Abstract

Introduction An ideal functional brace for anterior cruciate ligament-deficient (ACLD) patients should control anterior movement of the tibia and simultaneously decrease the effects of ground reaction shearing force. The current study was aimed to compare the interface pressure between the anterior shell of a functional brace and proximal of tibia in both sound and ACLD limbs, and to assess the effect of using functional brace on the symmetry of vertical and anteroposterior components of ground reaction force and impulse of ground reaction force during level walking. Methods Seven unilateral ACLD men participated in this study. The interface pressure between the anterior shell and proximal of the tibia and ground reaction force was recorded by means of Novel Pliance X and Kistler force platform, respectively. Wilcoxon ranked-sign test and factor analysis repeated measure analysis of variance were used to analyze data. Results The use of functional brace had no significant effect on interface pressure and peak points of the ground reaction force. By use of a functional brace, the valley and the impulse of the vertical component of ground reaction force on ACLD limb increased significantly (P < 0.05) and also improved limb symmetry of all parameters. The interface pressure was greater at distal contact points of the shell, which are at the middle level of the tibia crest. Conclusions The results suggest that functional brace could not apply force on proximal tibia especially at ACLD limb and therefore could not normalize vertical component of ground reaction force during level walking.

A Novel Force-Sensing Smart Textile: Inserting Silicone-Embedded FBG Sensors into a Knitted Undergarment

“…Its high flexibility has captured much research interest, and studies have used this device to measure bracing pressure. For example, the Pliance ® -X pressure sensor was used to measure the amount of pressure exerted by a posture correction girdle on AIS patients [16] and a functional brace on anterior-cruciate-ligament-deficient (ACLD) subjects [34].…”

“…The sensor was tested under two conditions: (1) placed between two glass clips to simulate the calibration system (Figure 5a), and (2) placed on the artificial skin (Figure 5b). The Pliance ® -X pressure sensor is a reliable tool for measuring low interface pressure between textiles and skin under stationary conditions [33][34][35]. Its very small and ultra-thin sensing area is connected to an extended conductive strip, which makes it favorable for insertion underneath long-sleeved clothing.…”

Investigation of bracing to unload muscle and knee contact forces for knee oteoarthritis patients: Modelling, workflow, prototype design and evaluation

“…The contact forces in this study are small in magnitude compared to GRF, which increases the influence of noise. These forces could be validated using pressure sensors between the brace and the leg similar to how Ghadikolaee et al did for a valgus brace [76]. Furthermore, this study has only investigated a momentary load reduction of a healthy knee joint, and it is unclear whether the prototype brace influences pain or provides any long-term effect on disease progression.…”