Anti-gravity treadmills are effective in reducing knee forces.

Area of Science:

• Biomechanics
• Rehabilitation Engineering

Background:

• Lower body positive pressure (LBPP) treadmills offer unweighting for enhanced recovery after lower limb surgery.
• Assessing the impact of LBPP on knee joint forces is crucial for optimizing rehabilitation protocols.

Purpose of the Study:

• To determine the efficacy of an LBPP treadmill in reducing in vivo knee forces.
• To investigate the relationship between LBPP settings, walking parameters, and tibiofemoral forces.

Main Methods:

• Subjects with instrumented tibial prostheses measured in vivo tibiofemoral forces.
• Testing occurred on an LBPP treadmill across various speeds, inclines, and pressure settings (25%-100% body weight unweighting).

Main Results:

• Peak axial tibiofemoral forces ranged from 0.8 to 5.1 times body weight.
• Knee forces significantly correlated with walking speed and treadmill reaction force (R²=0.77, p=0.04).

Conclusions:

• LBPP treadmills effectively reduce knee forces, showing potential for lower extremity surgery rehabilitation.
• The strong correlation allows for precise control of knee joint loading during early rehabilitation phases.