lateral instability

Question 1

what causes inversion/ eversion injuries?

Answer 1

unexpected loss of balance.

recurrent ankle sprains.

strains, muscle and/or tendon

sprains, ligaments (more serious) and avulsion fracture.

inversion vs eversion

Question 2

what are the three main ligaments affected by inversion injuries?

Answer 2

anterior talofibular ligament (ATFL)

calcaneofibular ligament (CFL)

posterior talofibular ligament (PTFL)

Question 3

what are the clinical test for the three main ligaments affected by inversion injuries?

Answer 3

anterior drawer (ATFL)

varus tilt (CFL)

PTFL is rate to injure due to its protected anatomical location.

Question 4

why are lateral ligaments more vulnerable to injury in relation to the medial ligaments?

Answer 4

lateral ligaments are not as thick and strong as the medial (deltoid) ligaments.

Question 4

does the foot have more inversion or eversion typically?

Answer 4

the foot typically has increased inversion/ supination ROM compared to eversion/ pronation ROM.

Question 5

what are the main inversion injuries?

Answer 5

avulsion fracture (tip of lateral malleolus) common during injury to ligaments.

the peroneus longus & peroneus brevis also resist supination moments and may be injured during a lateral ankle sprain.

Question 6

what are signs and symptoms of inversion injuries?

Answer 6

• ankle/foot pain
• swelling
• bruising
• decrease mobility of foot/ankle
• inability to bear weight
• pop sound at time of injury
• report of the ankle being unstable laterally.

Question 7

how can we see inversion/eversion injuries?

Answer 7

x-ray will not detect soft tissue damage.

if the patient has lost function of important ligaments, muscles or both.

this may predispose further injury as the ankle is unstable as the soft tissue function which stabilises the ankle has been lost.

this may predispose to accelerated osteoarthritic changes to the ankle and foot joints as a result.

Question 7

when is proprioception needed for inversion/eversion injuries?

Answer 7

physiotherapy is normally indicated to improve proprioception and strengthening to the peroneal muscles after lateral ankle sprains.

Question 8

what should happen if a patient is severely unstable due to inversion/eversion injuries?

Answer 8

if the patient is severely unstable or has severe pain, an MRI or ultrasound will be indicated to assess the extent of damage to the soft tissue structures

structure may then be indicated to repair soft tissue damage, followed by more physiotherapy

Question 9

what are examples of of foot orthoses that will resist supination moments?

Answer 9

• lateral forefoot wedge
• lateral forefoot wedge + combines lateral rearfoot wedge
• reverse morton’s extension.

Question 10

what is a reverse morton’s extension?

Answer 10

this is a forefoot extension plantar to the 2nd through 5th metatarsal heads. (2-5 forefoot extension)

same thickness (uniform) from 2-5 metatarsal heads.

Question 11

what are some footwear adaptions to resist supination moments?

Answer 11

• lateral flares/ floats
• or a discussion about using footwear that comes above the ankle and gives additional support to the ankle as a result (boot style).

Question 12

what can be used to provide medial and lateral stability to the ankle?

Answer 12

ankle bracing

if severe AFO

Question 13

when should you consider referral to physiotherapy after a clinical assessment?

Answer 13

if the patient presents with:
- laxity of the lateral ligaments
- history of instability
- pain within these ligaments
- weakness of the peroneal muscles.

Question 14

what is the long term consequence of joint instability?

Answer 14

irreversible joint damage, osteoarthritis (OA)