Ankle Mobility: Knee-To-Wall Test
Target: Ankle Dorsiflexion
Goal: To investigate issues potentially caused by too little or too much range.
When running, the shin & knee of the weight-bearing leg need to be able to pass over the grounded foot. For this to happen, the ankle needs sufficient range of dorsiflexion, i.e. distance the shin can move over the toes whilst the heel stays flat on the ground. Lack of ankle dorsiflexion can lead to the body seeking other ‘compensatory’ ways of getting that shin over the foot, including dropping the medial arch, external rotation of the foot, internal rotation of the knee, over straightening (extending) of the knee, bending forwards at the waist, dropping the pelvis (anterior pelvic tilt). Though such compensatory patterns are not always indicative of injury, over dependence on them may lead to either inhibition of performance or eventual tissue overload, pain and /or injury. The Knee-To-Wall Test is one of the standard ways used in clinic to test available ankle dorsiflexion as part of an investigation into why a runner may be experiencing pain higher up in the knee or hip.
- Facing a wall or mirror, take yourself down into a kneeling lunge position so that your toes are making contact.
- Lunge forwards to see if you are able to get your front knee to touch the wall or mirror without lifting the heel off the ground.
- If you manage a knee touch and the heel stays on the ground, move yourself a little further away from the wall and try again. Make sure your lunging knee travels directly forwards over the centre toe; if you allow it to drift inwards, the inner arch of the foot will fall and you will be able to get much further from the wall (giving a false result).
- Make a note of the maximum toe-to-wall distance achieved on that ankle (e.g. place a block) and then swap legs over to repeat the test for the other ankle at that distance. In the image below, the left ankle is seen to have less available dorsiflexion.
How Much Ankle Dorsiflexion Is Normal?
Defining a ‘norm’ is always a tricky task as human anatomy habitually shows natural variance. In healthy subjects, studies produce ranges of 5cm to 20 cm, with an average of 10cm. In terms of the position of your shin bone (tibia) to a vertical line, this is equivalent to an angle of 35-38o. Falling outside of 10cm may form a relevant part of a full investigation into ankle, knee or hip pain/ injury.
In many cases, the test becomes part of the exercise plan. Performing knee-to-wall lunges towards and also either side of a pole can be a useful way of increasing available dorsiflexion if an increase of range is required. It should also be noted that too much range may also be a factor in some injuries, in which case strengthening of the muscles around the ankle (particularly the soleus) may be more appropriate than stretching. If in doubt, as always, get checked by a suitable health professional.
Matt Phillips is a Running Injury Specialist & Video Gait Analyst at StrideUK & Studio57clinic in Sussex. Follow Matt on Twitter: @sportinjurymatt