What are the phases of the gait stance broken into according to O'Sullivan?

The phases of the gait stance, as described by O'Sullivan, can be broken down into five key stages: initial contact, loading response, midstance, terminal stance, and pre-swing. This classification is foundational in understanding the biomechanics of walking and is crucial for analyzing gait patterns, particularly in rehabilitation settings.

Initial contact marks the beginning of the gait cycle when the foot first strikes the ground. This phase is vital for shock absorption and sets the stage for the subsequent loading response, during which the body weight begins to shift onto the new stance leg. Midstance follows, where the body is directly over the supporting leg, and it is essential for balance and stability.

Terminal stance occurs as the heel of the stance leg rises, transitioning the body forward and preparing for the next phase, which is pre-swing. Pre-swing is the final phase of the stance in which the foot begins to lift off the ground, leading into the swing phase of the gait.

Understanding these phases helps clinicians assess and treat gait abnormalities, ensuring effective rehabilitation strategies that target specific weaknesses or dysfunctions.