A dynamic analysis of a functional brace for anterior cruciate ligament insufficiency

Abstract

A dynamic, in vivo, functional analysis of braces designed for ACL insufficiency has never been reported. In this study, 14 athletes who had arthroscopically proven absent ACLs were evaluated in the Biomechanics Laboratory at the Centinela Hospital Medical Center. None of the ligaments were repaired or reconstructed. Footswitch, high speed photography, and force place data were recorded while the athletes performed running and cutting maneuvers with and without their custom fitted C.Ti. braces (Innovation Sports, Irvine, CA). Cybex testing, KT-1000 evaluation, and radiographs were collected for each subject. Statistical analysis showed that while performing cutting maneuvers, braced limbs generated significantly increased shear forces compared to the same limb unbraced. During straight line running, braced limbs generated significantly less lateral and aft shear forces compared to the same limb unbraced. Running velocity increased while wearing a brace for most athletes, but this was not statistically significant. As expected, the sound limb generated significantly greater shear forces than the unbraced involved limb during most cutting maneuvers. Athletes who did not achieve 80% of the Cybex (Cybex, Division of Lumex, Ronkonkoma, NY) quadriceps torque of the sound limb generated significantly more forces during cutting maneuvers while wearing their braces. The cutting angle, approach time to the cut, and time on the force plate showed no significant differences during brace wear. We conclude that the C.Ti brace allows significantly better running and cutting performances for athletes who have torn ACLs. Athletes who have not achieved 80% of quadricep strength as measured by Cybex testing showed even more improvement while wearing their braces.(ABSTRACT TRUNCATED AT 250 WORDS)

Proprioception after anterior cruciate ligament reconstruction with and without bracing

“…These studies demonstrate that functional braces provide a protective effect for low anterior shear loads and internal-external torques applied to the tibia, but not at the high shear and torque values expected during sporting events [8,9,50]. Bracing appears to improve the performance of ACL-deficient subjects [18] but has limited effect in subjects who have undergone successful ACL reconstruction and rehabilitation [29,41]. There is little information regarding the effect of knee bracing on proprioception [27,32,37].…”

“…Most studies of the effect of knee bracing on subjects with ACL injuries or ACL reconstructions have involved biomechanical or clinical approaches [8,9,17,18,33,41,48,50]. These studies demonstrate that functional braces provide a protective effect for low anterior shear loads and internal-external torques applied to the tibia, but not at the high shear and torque values expected during sporting events [8,9,50].…”

Assessment of functional knee bracing: an in vivo three-dimensional kinematic analysis of the anterior cruciate deficient knee

“…Cornparisons between braced and non-braced conditions for the straight cut and cross cut revealed small increases in ground reaction forces with significant differences in the sagittal plane during the straight cut for the braced ACLD limb (Cook et al, 1989). Normal knees produced significantly greater sagittal forces while the ACLD leg was braced than when nonbraced dunng both cutting manoeuvres.…”

Alpineskiën met een brace?

“…Twee van de proefpersonen met op maat gemaakte braces waren sneller bij het afwerken van achtvormige circuits en plotselinge stopmanoeuvres dan bij het uitvoeren van dezelfde tests zonder brace. Cook et al (1989) gebruikten een op maat gemaakte brace om veertien sporters met niet-gereconstrueerde VKB-laesies te testen. Hardlopend afleggen van een recht parcours ging sneller met dan zonder brace.…”