Qualitative Anatomical Analysis Of The Lower Extremity During Stance Phase Of Gait Cycle

The Gait Cycle

This presentation will be on the gait cycle.

The gait cycle is defined as the manner of someone’s locomotion or ambulation leading to the repetition of the locomotion pattern involving strides and steps. In the process of covering the gait cycle, strides are made. One stride covers the whole gait cycle.

Contrary to the gait cycle is the run cycle. The gait cycle takes a third longer duration with lesser shock absorption compared to the run cycle. This would explain the tendency of runners having more overload injuries. Gait cycles involve the primary use of the lower extremities with the trunks and arms being used for stability and balance. In run cycles, the upper extremities are primarily depended upon with the trunk for balance, stability and propulsion.

The necessity of developing such classifications it to produce normal gait cycle of healthy movement that can be used in detecting pathological gaits. Hence, during the gait cycle of an individual, the poorly functioning muscles or joints can be detected.

This presentation will be focusing on the stance in the walking gait cycle.

The diagram generally splits the cycle into;

New gait terms/phases that are the initial contact, loading response, mid stance, terminal stance, pre-swing, initial swing, mid-swing and terminal swing.

Classical gait terms/phases that are the heel strike, foot flat, mid-stance, hell-off toe-off, mid-swing, heel strike.

The percentage of the stance and swing phases in one gait cycle.

The first sub-phase is the loading response phase. It begins just when the heel of one foot strikes the ground and ends when the other foot’s toe is lifted off the ground. During this phase, the body absorbs impact felt on the foot through rolling in pronation. Both the knee and ankle increase their flex degree as the hip slowly moves into extension.

The loading response takes up 10 percent of the walking gait cycle constituting the duration of initial double-limb support. In the occurrence of the loading response, the foot involved will come into full contact with the ground allowing the body weight to be transferred onto this stance limb. The start and the end of this subphase are represented by the figures (a) and (b) respectively.

This slide focuses on the ankle joint during the loading phase. During the ankle joint movement, as the heel strikes the ground, the joint drives deep into Plantarflexion. The movement results from action form muscles, the force of inertia as well as the force of gravity. All in all, the joint action is Plantarflexion with muscles involved being the pretibial muscles whose influence reduce as the ankle movement progresses. Ankle joint during this phase has their muscles eccentrically moving.

Next, we focus on the hip joint that initiates with flexion. However, the joint drives from flexion through to extension as the phase progresses. The action is therefore extension. This shift would probably be caused by muscle action as well as the force of inertia from the moving body. Hip joint movements are actuated by the hamstrings and gluteus maximus muscles whose action is concentric and isometric.

New and Classical Gait Terms/Phases

The last joint in this sub-phase would then be the knee joint. The knee comes in at flexion and as the phase progresses, it drives deeper into flexion. Hence the action is flexion. Such movement would probably be caused by muscle action as well as the force of gravity. In accordance with the active muscles, the quadriceps muscles are responsible. These muscles would act eccentrically to help produce the knee movement.

The second sub-phase is the mid-stance that begins when the opposite foot starts leaving the ground and goes on until the weight of the body finishes travelling along the foot’s lengths to be loaded over the forefoot. The ankle stiffens and the hips deeply flexed allowing stabilization of the body from the absorbed force at impact for forwarding propulsion.

The single support’s first half is represented by the mid-stance and it takes place from 10 to 30 percent duration of the walking gait cycle. In the occurrence of the mid-stance sub-phase, the start and the end are shown by figures (a) and (b) respectively.

Firstly, the joint in the study is the knee that comes in in a flexion state and shifts through to an extension. Hence, the action is an extension. Such movements are caused by muscles. Hence, the active muscles that are responsible are the quadriceps muscle that acts for a short while. These muscles act concentrically all through the phase making the knee joint move.

A point to note is that knee muscle is unnecessary at this sub-phase.

One more joint is the hip joint. The hip joint during this sub-phase comes in a flexion state before shifting through to an extension. To produce such a movement, the reaction has to come from the ground with little to no muscle action during the phase. Therefore it can be considered that there is no muscle activity.

It would be critical to note that the hip joint is passive during this sub-phase.

Lastly, we focus on the ankle joint that comes in in a slightly dorsiflexed state but drives deeper into dorsiflexion as the sub-phase progresses.  To produce such a movement, a group of calf muscles have to be activated combined with a force of inertia. It can, therefore, be concluded that the muscles responsible for the joint movement are the calf muscles acting eccentrically in reverse to produce the forward force.

Notably, the knee goes through an extensor moment.  

The third sub-phase is the terminal stance that begins when the lifted leg starts passing the leg on the ground and ends when the heel of the foot on the ground starts departing the ground. The weight of the body is divided and shifted over from the foot on the ground to the foot that is off the ground, propelling the body forward.

This stance takes up about 30 to 50 percent duration of the walking gait cycle allowing enough time for the body weight to move in front of the forefoot. It is represented by the vertical force graph’s ascending the second peak of the walking gait cycle.

Sub-Phases of the Stance Phase

The first focus will be on the knee joint. The knee joint comes in and begins extending as the sub-phase progress.  It extends to full extension. Therefore the action is an extension. Such knee joint movements are caused by the muscle action as well as the force of gravity. Thee muscles active in the process are the quadriceps muscles whose movements are eccentric.

A point to note is the maximum knee extension at this phase.

Next is the hip joint that comes in an extended state but shifts through to flexion as the sub-phase progresses. Hence, the action is flexion. Such hip joint movements are caused by muscles as well as the force of gravity. Muscles that are active during the phase are the psoas and iliacus major having a regular eccentric muscle action.

Notably, the hip goes through hyperextension.

We then look into the ankle join whereby the ankle joint comes in a dorsiflexed state before shifting through to Plantarflexion. Therefore, the action is Plantarflexion. Such a movement is enabled by the action form muscles as well as the reaction form ground. Hence, the active muscles include the powerful calf muscles that are able to contract concentrically.

Notably, there is a roll-off as well as push-off momentum with rapid knee flexion.

The last stance sub-phase is the pre-swing which begins when the opposite foot makes an initial contact with the ground and ends when the other foot’s toe gets off the ground. The phase facilitates the lifting of the foot from the ground and handing over of bodyweight to the other foot. The start and the end are shown by the figures (a) and (b) respectively.

To begin with, the first joint to be analyzed is the ankle joint that comes in flexed and drives deep into flexion as the sub-phase progresses. Therefore, the action is flexion. The movement of the joint is caused by the ground reaction with little to not muscle action around the join. Hence, during the sub-phase, the muscle around the ankle are passive.

Notably, there is passive knee flexion during this phase.

Next is the hip joint that comes in an extended but shifts through to flexion as the sub-phase progresses. Hence, the action is flexion. Such movement of the hip joint is caused by the action form muscle as well as the force of inertia. The active muscles are the rectus femoris and adductor longus that concentrically act.

A point to note is that this movement makes the body advance forward.

Lastly, is the ankle joint which comes in a plantarflexed state and maintains this state as the sub-phase progresses. Therefore, the action is plantarflexion. Such retention is made possible by the muscles as well as the necessary ground reaction. Active muscles are the calf muscles regularly contract concentrically.

Notably, the foot in the study is unloading the bodyweight to the other foot.

Lastly, the presentation concludes by stating that the gait cycle makes use of the movement in every part the body as well as the leg.

It is therefore critical to note the entire movement of the body while walking. Disorders may have consequences on one’s segment’s gait pattern. One example of a consequence of a disorder would be the reduced range of the knee flexion in patients that have undergone ACL reconstruction.