Anatomy & Stretching 101 Anterior Leg

Anatomy and Stretching 101

The anterior compartment of the leg Part A: Anatomy • The anterior compartment of the leg, or dorsiflexor (extensor) compartment, is located between the lateral surface of the shaft of the tibia and the medial surface of the shaft of the fibula.

• The anterior compartment is bounded anteriorly by the deep fascia of the leg and skin.

• The relatively small anterior compartment is especially confined and therefore more susceptible to compartment syndromes.

• Inferiorly, two band-like thickenings of the fascia form retinacula that bind the tendons of the anterior compartment muscles before and after they cross the ankle joint, preventing them from bowstringing anteriorly during dorsiflexion of the joint (Image A).

IMAGE A

Muscles of anterior compartment of leg • The four muscles in the anterior compartment of the leg are the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius (Image B).

• These muscles pass and insert anterior to the transversely oriented axis of the ankle (talocrural) joint and, therefore, are dorsiflexors of the ankle joint, elevating the forefoot and depressing the heel.

• The long extensors also pass along and attach to the dorsal aspect of the digits and are thus extensors (elevators) of the toes.

• Dorsi flexion is a relatively weak and short movement – only about a quarter the strength of plantarflexion (Soderberg, 1986), with a range of about 20° from neutral – dorsiflexion is actively used in the swing phase of walking, when concentric contraction keeps the forefoot elevated to clear the ground as the free limb swings forward.

• During standing, the dorsiflexors reflexively pull the leg (and thus the centre of gravity) anteriorly on the fixed foot when the body starts to lean (the centre of gravity begins to shift too far) posteriorly.

• When descending a slope, especially if the surface is loose (sand, gravel, or snow), dorsiflexion is used to “dig in” one’s heels.

IMAGE B

Part B: Stretching Once you understand the concentric action of the muscles, to stretch them you simply reverse these actions.

Reversing the actions of the muscles of the anterior compartment involves plantar flexion and if possible, toe flexion at the same time. If this is difficult, do one and then the other movement separately.

Toe Flexion EXTENSORS AND DORSIFLEXORS HOW TO STRETCH: Photo A - Clasp ankle and foot as pictured - Stabilise ankle - Press toes and top of forefoot down HOW TO CONTRACT: Photo A - Press toes up into hand

A

Major muscles stretched Tibialis anterior Extensor hallicus Extensor digitorum HOW TO RESTRETCH: Photo B - Bend toes further downwards towards sole of foot - Explore one toe at a time

B

Floor Tibialis Anterior EXTENSORS AND DORSIFLEXORS HOW TO STRETCH: Photo A - Sit on feet as pictured HOW TO CONTRACT: Photo A - Press top of feet into floor

A

HOW TO RESTRETCH: Photo B - Roll pelvis back

B

Major muscles stretched Tibialis anterior Extensor hallicus Extensor digitorum Photo C - Emphasise one leg - Lift knee higher from floor

C

Standing Toe Flexion • Standard: Any • Muscle Emphasis:Toe extensors

A

A. How to stretch Place dorsal metatarsals on floor if possible, with toes flexed.

Try to keep heel in contact with slant board.

Take some weight onto metatarsals to POT.

A. How to contract Press toes down into floor i.e toward extended position.

B

B. How to restretch Place more weight through foot.

Lean backwards moving knee above the foot that is stretching.

Keep foot in contact with slant board.

The Lying Tib Ant • Standard: Any • Spring Tension: Medium - Heavy • Muscle Emphasis: Entire anterior compartment including tibialis anterior, extensor hallucis and digitorum longus and brevis

A

A. How to stretch

Press carriage away and place top of one foot onto Jump board. Bend other knee slowly, controlling carriage movement with this leg. As carriage slides in allow foot and toes to plantar flex.

A. How to contract: Press foot back into jump board toward neutral position i.e. dorsi flex the foot.

B

B. How to restretch

Allow leg to bend further and carriage to travel in further.

Allow foot to plantar flex further.

What to watch out for: • Losing control of carriage movement. • Moving into stretch too quickly, “bouncing.”

Conclusion The stretches that require no equipment can be found in my book “StretchFit: Safe Effective Stretches for Every Body,” on Amazon books.

The final stretches on the Pilates reformer is from “Stretching on the Pilates Reformer: Essential Cues and Images” on Amazon books.