This month we start the first in a new series of the Rehab Masterclass.
The focus for this month is down south – on the feet. There are many textbooks and websites that offer rehab ideas on how to manage musculoskeletal injuries. The series will present some very basic and effective ideas on how to implement direct muscle retraining exercises that are easy, inexpensive and suitable for any rehab professional to use to rehab an injured joint.
What is being rehabilitated?
The plantar arch of the foot is supported by a highly complex and organised layer of small muscles and connective tissues that aim to support the foot during weightbearing activity. Furthermore, the arch is supported by longer extrinsic muscles originating on the shin but finishing in the arch of the foot such as the flexor hallucislongus, tibialias posterior, tibialis anterior and flexor digitorumlongus. The foot is designed to pronate (or flatten) during stance phase of gait. This allows the bones of the foot to unlock and accommodate for changes in terrain and to absorb the shock of the ground reaction force. However, control of this pronation is very finely tuned. Too much stress is placed on supporting soft tissue tissues such as the plantar fascia, Achilles tendon and the supporting muscles. Too little pronation and shock is not absorbed and the shockis transmitted to the bones of the foot and shin.
Furthermore, excessive pronation will also cause the tibia to internally rotate. This then forces the knee to turn inwards during gait and this places stress on the patellofemoral joint. Finally, this tibial internal rotation sets of a chain of biomechanical reactions whereby the hip also internally rotates and adducts. This places stress on hip muscles and the lower back.
Therefore having a strong plantar arch and long extrinsic muscle system that controls pronation will be a necessary part of many lower limb injuries.
What sort of injuries would benefit?
1. Ligamentous injuries to the midfoot.
The most common midfoot ligament injury is the Lisfrancs injury. This is an injury to the short ligaments that support
the cuneiform bones to the 1st and 2nd metatarsals. They are commonly injured in bad ankle sprains or in direct overpronation injuries to the foot where the foot is forced
to flatten under a load. Damage to the Lisfranc ligaments can lead to an unstable arch that may predispose the sufferer to
long term midfoot pain. The unstable Lisfranc injuries need to have surgical stabilisation whereas the stable version can
respond well to protection and retraining of the foot muscles.
2. Injuries caused by overpronation.
Typically a foot that pronates for too long or pronates too far can cause a plethora of foot and lower limb overuse injuries such as
plantar fasciitis, shin splints, Achilles tendon problems, and patellofemoral problems.
3. Stress injuries to the foot.
Stress fractures of the navicular and metatarsals are a common consequence of repeat
loading of the foot in walking (army recruits), running and special populations such as ballet dancers. Having a more
tolerant system of arch muscles will help to absorb shock from the ground reaction force which will then offset bone loading.
When to do these exercises?
The following sequence of exercises include non weightbearing as well as weightbearing options. In nasty ligament
injuries and stress fractures of the foot, often the victim is placed in a weightbearing boot or ‘moon boot’ to
offload the foot structures to allow a healing environment to be created. In these instances, the foot can be removed
from the boot and the non weightbearing exercises can be performed. In injuries that tolerate weightbearing
such as shin splints, Achilles tendon problems, plantar fascia problems, then full weightbearing is allowed and the
patient can progress to the more advanced exercises in the list.
1. Towel scrunchies.
These have been used for years by therapists to strengthen the muscles that support the arch of the foot. a. Place a towel on a tiled or wooden floor
(carpet won’t work).
b. Place the foot relaxed on the towel with the foot in line with the knee and hip. The toes should be pointing directly ahead.
c. Initiate the movement by attempting to firstly lift the arch. Think about drawing the ball of the foot towards the heel. You will see the arch will lift.
d. Next use all the toes to curl the towel under the foot.
e. Relax the foot and start again.
f. This exercise does not cause any soreness the next day, what will be felt is that the arch muscles will start to fatigue.
g. The progression is seated, to standing on two legs and standing on one leg.
2. The cup drop.
This is an interesting and novel way to integrate both intrinsic arch muscle function and extrinsic antipronator
muscle function with hip stability muscles, in particular the gluteus medius and maximus. During weightbearing, the
gluteus medius muscle prevents the hip from internally rotating and adducting, and this action works well with the arch
muscles preventing excessive pronation.
a. Place some small objects such as marbles about 1 foot in front of your body.
b. Reach forward with the foot and pick up the marble with the toes. This action of clawing the marble with the toes will
stimulate the arch muscles.
c. Whilst holding the marble in the toes, circle the hip outwards to the side of the
body and then behind the body and place the marble in a cup placed at 45 degrees to the hip.
d. It is important that the foot stays turned outwards during the circle movement as this keeps the gluteus active.
3. The matt balance.
This exercise adds contraction of the calf muscles, the gastrocnemius and soleus, and incorporates
these with the arch muscles. To make the exercise extra challenging, the drill is performed on a soft matt. The soft matt
surface creates an unstable situation, and there is mounting evidence that suggests that by adding an element of balance
control into a rehab exercise is not only a novel way to perform an exercise, but may in fact be necessary as the perturbations in
movement stimulate all the small position feedback nerve endings that control proprioception. The proprioception nerve
endings feedback into the muscle control system and this potentiates the stimulation of the control muscles.
a. Place a soft matt on top of a 6mm piece of timber or hard rubber matt. The softer the matt the harder the exercise.
b. Stand on the matt but only with the 3rd, 4th and 5th toes in contact with the matt. The 1st and 2nd toes should be hanging
unsupported by the matt.
c. This position of the foot creates a situation whereby the foot wants to turn
in under the influence of gravity. The arch muscles and the long antipronation muscles in the shin have to control the inside of the foot to keep it up
and off the floor.
d. Attempting to keep balance (and this will be difficult if the matt is too soft), slightly raise the heel to engage the calf muscles.
e. Hold this position for 1-2 seconds and then slowly lower down to the start position.
f. Perform 3 sets of 10 repetitions.
4. Lunge with towel scrunchie.
This exercise is a high level integration exercise that combines arch muscles and gluteals whilst performing a functional exercise
such as the lunge. This type of exercise is done in late stage rehab prior to running as the muscle activation patterns more
closely resemble what should happen when running in terms of limb support – that is, the arch muscles control pronation,
the quads control the knee and patella and the gluteus medius supports the hip during foot strike.
a. Stand on a towel, similar to exercise 1 above.
b. Wrap some theratubing around a post and also wrap around the upper tibia. The band needs to be directed to pull the tibiainwards, not outwards. This pulling in of
the tibia will cause the upper leg to follow and this is imitating hip adduction and internal rotation. The goal of the exercise
is to prevent this by keeping the kneecap aligned with the 3rd toes. The gluteals now have to work to allow this to occur. If
they didn’t, the knee would drop inwards and way from the 3rd toe.
c. Slowly lower down into a lunge whilst maintaining the tracking of the kneecap over the 3rd toe and also keeping the
towel scrunched up under the foot.
d. Raise back up to full knee extension. Rest. Start again.
When it comes to rehabilitating lower limb injuries, the exercise professional needs to keep in mind that muscle imbalances in the
lower limb tend to be stubborn. That is, they don’t want to change. Therefore when programming for lower limb rehab, it is
necessary that the patient is performing muscle control exercises quite regularly throughout the day to stimulate the motor
patterns to become more entrenched. Performing these exercises only every 2nd day is not enough to induce a change in the
supporting muscles of the lower limb.