A New Type of Knee Brace Could Change How Athletes Prevent Injuries—Without Slowing Them Down

A revolutionary knee brace design using tensioned cables significantly reduced dangerous knee movements that lead to serious sports injuries in an exploratory study. Researchers found the innovative brace reduced peak knee valgus angle from 7.9 degrees to 4.5 degrees and lowered peak external knee abduction moments during lateral shuffle movements—the exact motions that commonly cause anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries.

Why Do Traditional Knee Braces Fall Short?

Current knee braces face a frustrating trade-off: rigid braces provide some protection but often hurt athletic performance by reducing sprint speed, agility, and jump height. Meanwhile, soft sleeve-type supports feel comfortable but offer minimal mechanical protection when athletes need it most. This creates a dilemma for the more than 200,000 Americans who suffer non-contact ACL injuries annually, with combined costs exceeding $7 billion per year.

The consequences of knee ligament injuries extend far beyond the initial trauma. ACL injuries carry a 37% reinjury rate after athletes return to activity, and many lead to early-onset osteoarthritis, premature retirement from sports, and persistent performance deficits.

How Does the Cable-Based Brace Work Differently?

The Stoko K1 knee bracing system represents a completely different approach to knee protection. Instead of rigid frames and hinges, it incorporates an adjustable network of tensioned Dyneema cables within a compression garment. Unlike rigid braces, the cable system is designed to maintain athletic performance while providing protection, though direct performance testing was not included in this exploratory study. The design mimics how muscles and ligaments naturally support the knee, providing customizable mediolateral support while preserving the freedom of movement athletes need.

Ten physically active adults with a mean age of 21.7 years participated in the study, performing submaximal lateral shuffle movements under three different conditions. The researchers measured three-dimensional knee movements and ground reaction forces to assess how well each approach protected the knee during injury-prone motions.

What Did the Research Reveal?

The results were striking when comparing the tensioned cable brace to going unbraced:

• Knee Valgus Reduction: Peak knee valgus angle dropped from 7.9 degrees to 4.5 degrees—representing approximately a 43% relative reduction in the dangerous inward knee collapse that often leads to ACL tears
• Moment Reduction: External knee abduction moment decreased from 2.0-2.1 Newton-meters per kilogram to 1.6 Nm/kg, indicating significantly less stress on knee ligaments
• Design Innovation: The cable system applies support at anatomical locations where natural structures like muscles and ligaments provide stability, rather than imposing artificial constraints through external frames

These improvements occurred during lateral shuffle tasks that specifically mimic the movements most associated with non-contact knee injuries in sports like soccer, basketball, and volleyball. The eccentric phase—when muscles lengthen while contracting to control movement—is particularly critical because this is when most ACL injuries occur during rapid direction changes.

The cable-based design offers several advantages over traditional approaches. The adjustability allows for customized support that can be fine-tuned for individual athletes, while the compression garment format aims to improve comfort and likely increase adherence compared to bulky rigid braces. Previous research has shown that comfortable equipment can reduce injury rates by 1.5-13.4% compared to control versions.

While this exploratory study shows promising initial results, the researchers note that more extensive testing will be needed to fully validate the approach across different sports, movement patterns, and athlete populations. However, the significant biomechanical improvements suggest this technology could represent a major advance in sports injury prevention, potentially helping athletes stay protected while addressing the performance compromises that rigid braces often impose.