Ankle function and Conditions
PTA 104 Orthopedic Dysfunctions

Introduction

The following information is used for instructional purposes for students enrolled in the Physical Therapist Assistant Program at Lane Community College. It is not intended for commercial use or distribution or commercial purposes. It is not intended to serve as medical advice or treatment. Contact howardc@lanecc.edu for permissions.

Objectives

Review anatomy and muscles of ankle and foot.
Review kinematics of ankle and foot.
Identify signs and symptoms of compartment syndrome
Describe common non-surgical management principles of hypomobility conditions.
Describe common overuse ankle injuries and describe the associated causes and impairments
Identify common ligamentous injuries of the ankle
Select appropriate exercises and training activities based on recovery stage for the treatment of ligamentous injuries for surgical and non-surgical cases.

Video Supports

Approximately 60 minutes of videos are included to support application knowledge of textbook and lecture material.

Anatomy Review

Now, let's look at some important muscle actions that may have been hard to glean from the text. These are separate from the muscle actions described in anatomy texts.

Functional muscle roles: Posterior tibialis controls and reverses pronation at mid-stance as well as supports the arch of the foot (picture its insertion).
Flexor hallucis longus and digitorum longus support the medial longitudinal arch.
Peroneus longus and peroneus brevis pronate at the subtalar joint and peroneus longus supports the transverse and lateral longitudinal arch.
Soleus prevents dorsiflexion of the tibia due to the effect of gravity during static stance.
Gastrocnemius controls anterior translation of the tibia during stance phase. This can also be termed as eccentrically controlling dorsiflexion in closed chain.

Compartment Syndrome

There are four anatomical compartments in the lower leg:

anterior: foot dorsiflexors
lateral: everters and retinaculum
superficial posterior: plantar flexors
deep posterior: foot flexors

When there is a fracture, hemorrhage, crush injury, burn, or prolonged compression, and emergency situation can develop due to extreme pressure on nerves and vessels in the affected limb. The limb is often swollen, severely tender, and there may be skin changes (shiny, darkened) There are 5 "P"s when assessing for possible compartment syndrome, and indicators are a medical emergency:

pain
paralysis
parasthesia
pallor
pulses (diminished)

Patients with overuse injuries in the foot and ankle can develop non-emergent compartment syndrome over time due to prolonged and persistent inflammation and resultant swelling

Kinematics

Lets begin with a few highlights about joint kinematics of particular importance.

Here is an animated review of all motions.

The closed chain animations for talocrural joint start at about 3 minutes. The closed chain animations for the subtalar joint run from 5:50-7 minutes:

Remember, the foot is built for weight bearing and it is the base of support for the ambulatory human body. Think about the muscles and the joint kinematics in terms of their function in closed chain positions.

The closed packed position is dorsiflexion and the open packed position of the ankle joint is plantar flexion. Open packed positions have the highest risk of ligamentous injury. In a closed chain plantar flexion at the ankle, the subtalar and transverse tarsal joints are closed packed. This puts a rigid lever designed to transmit forces at the distal end of an at risk joint complex (the open packed ankle). This is why inversion ankle sprains are so common place, and the most frequent mechanism of ankle sprain. Any footwear with an elevated heel increases ligament injury risk. The greater the heel elevation, the more danger of joint injury.

Pes planus, pronated foot, flat foot all mean decreased medial longitudinal arch.

Pes cavus or supinated foot means high-arched foot.

When the foot is weight bearing, subtalar motion and tibial motion are inseparable. External rotation of the tibia results in supination of the subtalar joint, or vice versa. Internal rotation of the tibia results in pronation of the subtalar joint.

In pronation, the ligaments of the forefoot and midfoot unwind allowing the bones more movement. This is so the foot can conform to the ground and better absorb forces, this happens during foot strike. In supination, the forefoot and midfoot ligaments are all wound tight, this allows for a rigid lever to push off of. This also has a very important effect on ROM. When stretching to increase dorsiflexion ROM, have the foot in supination. This transmits the force of stretching to the talocrural joint. If the foot is allowed to fall into pronation, a lot of midfoot dorsiflexion can occur. This both gives the false appearance of true ankle dorsiflexion, and prevents the desired stretch.

Functional ROM for gait purposes is 7 degrees of dorsiflexion, 25 degrees of plantar flexion and 40-50 degrees of toe extension. Make particular note of the dorsiflexion and toe extension measurements. These factors along with at least 3/5 dorsiflexion strength are required for adequate foot/toe clearance during swing phase of gait.

Common Conditions

Note linked videos describing conditions - Approximately 35 minutes

Condition	Causes	Patient presentation	Management and Treatments
Pes Planus (flat foot)	structural and biomechanical	Loss of longitudinal arch	Supportive footwear, orthotics, calf stretching
Hypomobility (stiff foot)	structural and biomechanical; degenerative changes	Impaired joint mobility and ROM, pain, impaired gait cycle or balance reactions	Restore ROM, restore joint accessory motions, stretch tight/shortened musculature, strengthen weak musculature, footwear and orthotics with added cushion (soft shoe)
Lateral inversion sprain (Link to 15 minute tutorial)	excessive ligament loading during inversion	swelling, tenderness, and brusing (Grade III)	Protection phase: Pain and swelling control, PRICE, gentle ROM, toe intrinsic AROM, casting or splinting as needed and reduce weight bearing Controlled motion phase: basic balance training exercises, calf strengthening (from double to single limb support), lower extremity strengthening Return to function phase: progressive balance activities with multi-directional challenge, agility drills and sports-specific training Lateral ligament surgical repairs: always start with open kinetic chain strengthening, everter strength is the most important to recover, and no proprioception and balance training until weight bearing is fully pain free. The maximum protection phase last 4-6 weeks. ROM of the ankle is often not allowed at this time. The moderate protection phase allows for restoring ROM, and at 6 weeks post-op, full weight bearing is commonly allowed.
High Ankle Sprain (Link to 5 minute video) Closed captioning (CC) may help with the accent	excessive loading during eversion, straining the syndesmosis between tibia and fibula; may require surgical intervention	Tenderness above ankle	Protection phase: Use of crutches and walking boot to allow ligaments to heal; rehab course following immobilization is similar to lateral ankle sprain Controlled Motion Phase: Progress weight bearing as tolerated Increase ROM Begin strengthening-isometric to eccentric-concentric, OKC to CKC Begin proprioception training and simple balance training Return to Function Phase: Add resistance to strengthening exercises Utilize BAPS/Wobble boards full WB Progress jogging to running, straight lines before incorporating turning/changing directions Progress jumping beginning with eccentric loading phase, moving on to concentric jumping Plyometric strengthening
Achilles Tendon Rupture (Link to 5 minute video)		Pain, swelling and palpable defect along posterior calcaneus. Plantar flexion weakness, inability to climb stairs, jump or rapidly change directions with affected extremity. +Thompson Test	Maximum Protection: Maintain immobilization as directed by MD/surgeon. Instruct crutch ambulation as weight bearing restriction, PWB non surgical, non-weight bearing surgical RICE Maintain ROM of non-immobilized structures Prevent reflex inhibition by use of gentle isometric setting of immobilized tissues Maintain fitness Achilles conventional repair: Weight bearing will be prohibited for 4-6 weeks and immobilization will usually last 6 weeks, low intensity resistance exercises don't begin until 6-8 weeks, and no closed chain exercises until full weight bearing is pain free. This approach is utilized with anyone who had delayed repair of the the rupture.
Plantar fasciitis (PF) or Plantar heel pain Link to 10 minute tutorial	prolonged standing and walking, obesity, foot structure (planus or cavus)	Pain on plantar surface of foot, near fascial insertion on medial heel. Results in pain upon palpation, pain with weight bearing, especially first thing in morning, climbing inclines, or with toe extension	Rest, may need walking boot Cushioned footwear and possible rocker bottom shoe and/or medial heel wedge, strengthening of foot intrinsics, particularly toe flexors, gastroc and plantar foot stretching, soft tissue mobilization A clinical treatment recommendation: For applying cross friction massage for plantar fasciitis, a golf ball is an excellent tool that can be used by both the therapist and the patient.
Tibialis anterior tendonitis ("shin splints")	kicking in plantar flexion, running hills or hard surfaces	Pain in anterior shin with active dorsiflexion or plantar flexion stretching. Weak anterior tibialis, hypomobile gastrocnemius/soleus, and excessive pronation	icing, stretching tibialis anterior and gastroc soleus, strengthening, orthotics as needed
Tibialis posterior tendonitis	over pronation and pes planus; activities that stress control of pronation (e.g. rapid pivoting)	Pain posterior to medial malleolus; may extend into the musculotendinous junction into medial shin	icing, stretching tibialis anterior and gastroc soleus, strengthening, orthotics as needed

Sample Rehabilitation Programs

Early Ankle Sprain Rehab

Approximately 8 minutes

Controlled Motion Ankle Sprain Rehab