SF POSTERIOR MUSCLES

DEEP POSTERIOR MUSCLES

Lateral muscles

ANTERIOR MUSCLES

Muscles act simultaneously on the ankle and subtalar joints

Comprises the major bulk of calf muscles

Proximal attachments partially adhere to the capsule of the knee joint

Medial head is larger than lateral head of gastrocnemius

Lies between gastrocnemius and soleus

Very small fusiform muscle with a very long tendon

Absent in some individuals

Thought to provide some assistance to gastrocnemius and soleus in plantarflexion

Triceps suras muscles

Responsible for plantarflexion

How many percent of total torque in plantarflexion for triceps surae

Average force exerted by triceps surae is ______x the body weight, which gradually increase _____ at age ___

Greater forces are expected if knee is in ______ during plantarflexion due to improved length tension relationship

Has higher proportion of fatigue resistant slow twitch muscle fibers

Serve as postural muscle

Deepest calf muscle close to the interosseous membrane and covered by the triceps surae

Proximally has a central position between the fdl medially and fhl laterally, distally takes a more medial course

Spreading of distal attachments provides tendomuscular support on the plantar side of the foot to maintain the medial longitudinal arch

Found medially in calf

In the leg, it crosses over the tp so its tendon lies behind the tp tendon at the malleolus

Each tendon perforates the corresponding tendon of the short toe flexors

Located under the soleus on the lateral calf

2x Larger cross sectional area

At the foot, the tendon passes between two sesampid bones of the first MTP

Functions similarly to the transverse carpal ligament of the wrist

Active inverter

Produces inversion in any position of the ankle

Serve important roles in CKC activities

Dynamically supports the foot arches because of its extensive attachments at the foot

Weakness of tp

TP is the most active inverter during what phase

Contract to support the longitudinal arch

Resist hyperextension of the MTP to maintain person’s COG

Clawing of the floor

In terms of location, appears as a direct continuation of the biceps femoris

Muscle fibers converge to form tendon that passes in a groove behind the lateral malleolus, then to the cuboid

As it enters the plantar surface of the foot, it follows a groove that runs anteriorly and medially

Larger CSA and produces greater torque

Tendon passes behind the lateral malleolus to cross the calcaneus and cuboid

Nearly covered by the pl, but can be felt separately from the longus in the lower leg

serves as the main everters of the subtalar joint at any position of the ankle

Also classified as plantarflexors but offers poor leverage

In CKC, it provides the major support to the arches, adjustment of the foot to the ground and controls the leg on the plated foot

Stabilized the first TMT jt to counteract the lateral pull of ta

Most active during the last half of the stance phase

This muscle isometrically pushes the first ray into the ground to stabilize it

Pretibial muscles

Anterior muscle group is separated from the lateral group via

Contributes to the roundness of the leg anteriorly

Leg loses concavity if atrophied or palayzed

Can be palpated through its entire length; becomes tendinous well above the ankle joint

Upper portion is covered by ta and edl

Tendon passes over the dorsum of the ankle and laterally to ta tendon

Can be palpated in the distal half of the leg

Difficult to delineate one from the other in their upper portions

Most lateral to the edl

Superficial and sits between the peroneal muscles laterally

Sits between peroneal muscles medially

Primary dorsiflexor

Extensor muscles are not effective in producing dorsiflexion. That is why, when ta is weak, there will be no muscles that can compensate for dorsiflexion

An isolated _____ ______ creates strong eversion of the ankle

Also and inverter of foot, and controls the descent of the longitudinal arch as the foot makes contact to the ground

Weakness of the ta and extensors result to

Keep the foot dorsiflexed during the swing phase of gait

Prevents toe drag

Foot only weighs __ lbs, so muscular contractions are weak; ______ if a person is standing on _____ _____

Muscles are difficult to palpate because of the thick plantar fascia and are separated into 4 layers

Act more as a group and are used to provide stability or balance and for providing support and assistance to the foot during activities

Supports the medial longitudinal arch and is active during the last part of stance phase

Assists in turning the foot into a rigid lever for propulsion

Stabilize the MTP and maintain toes in extension to assist the forceful pull of the flexors during push off of the foot

Assists their extrinsic counterparts in toe extension

If the toes are unable to extend during gait, the intrinsics are unable to provide assistance during push off. This results in a longer stride

Smelly feet is caused by

While the talocrural and subtalar jts are interrelated, pronation and supination occurs at the _______ joint and also involve the relationship of the talus and calcaneus

Calcaneus moves freely in all planes

In OKC, calcaneus is free to move in what plane

In OKC, the talus moves in what plane

One of the most important joints in supination/pronation

Vital to maintain foot contact with the ground

Produces the most movement in supination/pronation

Transverse tarsal joints are locked into position in ______; can move either supination/pronation during pronation of the rearfoot to accommodate irregular surfaces

Function of foot arches

The three arches, bony structures, dynamic ligament-fascial support and static muscle contraction provide the foot with the ability to change the foot between a flexible and rigid structure

The arches distribute weight to different parts of the body posteriorly

The arches distribute weight ro different parts of the body anteriorly

Medial longitudinal arch bones

Lateral longitudinal arch bones

Transverse arch

Metatarsals are curved, with the ______ in the _____ aspect, which allows acceptance of larger forces

Extends from calcaneal tuberosity to the toes

Serves as a tie rod which acts as a truss to further support the arches and prevent displacement of the calcaneus and metatarsal heads in weight bearing

Actively reinforced by the intrinsic and extrinsic muscles of the foot

Creates a rigid structure

Further supports the longitudinal arch when the MTP jts are hyperextended

Active concentric contraction of the _______ extrinsic and intrinsic muscles = higher arch