Intro:

For people who depend on a knee-ankle-foot orthosis (KAFO) to walk safely, small improvements in joint technology can make a big difference in daily life. A new study published in the Journal of Prosthetics and Orthotics explored whether adding a reactive-dynamic orthotic ankle (RDA) joint can improve gait and comfort compared to conventional ankle joints (CAJ).

Key Findings:

  • Improved movement: The RDA allowed greater ankle motion (7°–12° more dorsiflexion) and smoother push-off during walking and ramp ascent.
  • Reduced strain: The RDA reduced knee extension forces by up to 0.13 Nm/kg, making it easier to start the swing phase.
  • Better function on uneven surfaces: Patients felt the RDA made walking on inclines and declines easier and more natural.
  • High user satisfaction: Participants reported higher usefulness scores for RDA-equipped KAFOs versus conventional joints.
  • Reliable performance: The microprocessor-controlled C-Brace maintained near-perfect reliability (close to 100%) for stance-to-swing transitions regardless of ankle joint type.

Why It Matters:

The study confirms that reactive-dynamic ankle joints offer measurable biomechanical and patient-reported benefits, particularly in walking on ramps and uneven terrain. For clinicians, this means KAFO fittings can be optimized further—not just by selecting the right knee joint mechanism (such as C-Brace or iveE-MAG Active), but also by upgrading the ankle joint to a reactive-dynamic design.

For patients, this translates to smoother walking, better balance, and less fatigue in everyday movement.

Conclusion:

Adding a reactive-dynamic ankle joint to a KAFO can improve mobility and comfort for users with complex lower-limb weakness. If you or your patient use a KAFO, talk to your prosthetist or orthotist about whether an RDA joint—such as the Nexgear Tango—might enhance gait efficiency and safety.

Reference:

Schmalz T, Rauch S, Drewitz H, Bellmann M, Kannenberg A. The Use of Reactive-Dynamic Orthotic Ankle Joints in Different Types of KAFOs: Results of Biomechanical Tests and Patient Evaluations. Journal of Prosthetics and Orthotics. 2025;37(4):221–229.