[NGN] 2023 FUNDAMENTALS OF NURSING [NUR 211] -GAIT ANALYSIS SIMPLIFIED CLASS NOTES

[NGN] 2023 FUNDAMENTALS OF NURSING [NUR 211] -GAIT ANALYSIS SIMPLIFIED CLASS NOTES Gait cycle Walking is the most convenient way to travel short distances. Free joint mobility and appropriate muscle force increases walking efficiency. As the body moves forward, one limb typically provides support while the other limb is advanced in preparation for its role as the support limb. The gait cycle (GC) in its simplest form is comprised of stance and swing phases. The stance phase further is subdivided into 3 segments, including (1) initial double stance, (2) single limb stance, and (3) terminal double limb stance. Each double stance period accounts for 10% of the GC, while single stance typically represents 40% (60% total). The 2 limbs typically do not share the load equally during double stance periods. The swing phase for this same limb is the remaining 40% of the GC. Ipsilateral swing temporally corresponds to single stance by the contralateral limb. Slight variations occur in the percentage of stance and swing related to gait velocity. Duration of each aspect of stance decreases as walking velocity increases. The transition from walking to running is marked by elimination of double support period(s). A stride is the equivalent of a GC. The duration of a stride is the interval between sequential initial floor contacts by the same limb. A step is recognized as the interval between sequential floor contacts by ipsilateral and contralateral limbs. Two steps make up each GC, which is roughly symmetric in normal individuals. GC phasing A consistent sequence of motions is performed at each of the lower extremity joints during locomotion. Each stride contains 8 relevant phases. Stance is comprised of 5 gait phases (ie, initial contact, loading response, midstance, terminal stance, preswing), with the remaining 3 phases occurring during swing. The first 2 gait phases (0-10% GC) occur during initial double support. These phases include initial contact and the loading response. Initial contact often is referred to as heel strike. While this term is appropriate in normal gait, many patients achieve heel contact later in the GC, if at all. The joint motion during this phase allows the transfer of weight onto the new stance phase leg while attenuating shock, preserving gait velocity, and maintaining stability. Swing phase by the contralateral limb corresponds with single support by the ipsilateral limb to support body weight in the sagittal and coronal planes. The first half of single support is termed midstance (10-30% GC) and is involved with progression of the body center of mass over the support foot. This trend continues through terminal stance (30-50% GC). This phase includes heel rise of the support foot and terminates with contralateral foot contact. [1] The final stance element, preswing (50-60% GC), is related functionally more to the swing phase that follows than to the preceding stance phase events. Preswing begins with terminal double support and ends with toe-off of the ipsilateral limb.