Walking Kinematic Coordination Becomes More In-Phase at Extreme Inclines

Area of Science:

• Biomechanics
• Human locomotion
• Kinesiology

Background:

• Walking on inclines alters mechanical energy, kinematics, and muscle activation.
• Extreme inclines (above 15%) necessitate different muscle activation and coordination patterns.

Purpose of the Study:

• To analyze changes in lower-extremity kinematic coordination during walking at increasing incline angles.
• To investigate how joint coordination shifts with steep inclines using continuous relative phase analysis.

Main Methods:

• Twelve healthy adults walked at 3 mph on a treadmill across seven inclines (0% to 30%).
• Kinematic data were collected, and continuous relative phase was calculated for hip-knee, hip-ankle, and knee-ankle joint couplings.
• Coordination patterns were assessed across different incline levels.

Main Results:

• Significant differences in coordination were observed between 0% and 30% inclines, particularly in the hip-knee and hip-ankle couplings.
• All three joint couplings became more in-phase at inclines exceeding 15%.
• The hip-knee coupling showed a notable shift from out-of-phase to in-phase coordination between 10% and 15% incline.

Conclusions:

• Steep incline walking elicits significant shifts in lower-extremity joint coordination.
• Increased in-phase joint coupling above 15% incline suggests adaptive strategies for stability and propulsion.
• Understanding these coordinative strategies is crucial for analyzing human adaptation to challenging terrains.