Complexities of the ankle joint
The ankle is primarily considered a hinged joint in which it only allows
one plane of motion, similar to a hinge on a door. This means that the
ankle itself is responsible for up and down motion, or what we refer to
as dorsiflexion (up) and plantarflexion (down). However, the ankle is
truly much more complex than this. It is comprised of three bones: the
tibia (shin bone), fibula (bone on the outside of the ankle), and the
talus. These bones are held closely together at the angle by over nine
ligaments (with many of these ligaments having multiple segments of their
own), thereby providing excellent stability. Interestingly, the talus
is one of the few bones in the body that has only ligaments attached to
it and does not have any tendons attached to it.
In addition to the ankle joint itself, it is important to consider the
joint underneath the ankle, which is termed the subtalar joint. This is
comprised of the talus and the calcaneus (heel bone). This is important
to consider as well as this joint is primarily responsible for the inward
(inversion) and outward (eversion) motion that occurs through the ankle
and foot. This joint also has its’ own ligaments that provide further
stability. Lastly, there is additional motion across the joints just further
down from the ankle, termed the transverse tarsal joints, which also provide
motion in all planes.
Ankle mobility / Stability
The collective anatomy of the ankle, subtalar, and transverse tarsal joints
are important for the overall function, motion, and stability across the
ankle. The unique anatomy to the bones around the ankle provide inherent
stability, however the complex of ligaments around the ankle are especially
important in maintaining stability. The ankle is not as mobile as some
of our larger joints, such as the hip, however due to the need for the
foot and ankle to move both up and down but also inwards and outwards,
there is an innate tradeoff for stability. The primary stabilizers of
the ankle are the ligaments around the ankle however the secondary stabilizers
are the tendons that cross the ankle joint. This means that when the ligaments
are injured, the tendons often have to work harder to maintain stability,
thereby putting them at risk for injury as well. Ultimately, instability
can occur in most of the joints in our bodies if there is injury to either
the bones or the ligaments that maintain this stability. One major reason
the ankle may be more susceptible to injury and subsequent instability
is due to the complex three dimensional function of these joints in combination
with the types of activities we are involved in, both within our day to
day life as well as more strenuous / physical activities. Simply put,
the foot and ankle are the foundation for our body and are in use with
almost all activities of daily living.
There are multiple different ‘types’ of ankle instability depending
on which ligaments are injured. However in general, when we refer to ankle
instability it is due to an ankle sprain, in which there is an inversion
(inward) ankle injury. When this happens, the ligaments on the outside
of the ankle are either stretched or torn. The injured ligaments in this
situation are the anterior talofibular ligament (ATFL) and calcaneofibular
ligament (CFL). These ligaments specifically prevent the ankle from shifting
forward (anteriorly) and inward (inversion), therefore when injured patients
are more susceptible to repeat injury. After an ankle sprain, these ligaments
will typically heal, however they do not always heal as tight as they
should, thereby resulting in an increase in abnormal motion across the
ankle and subtalar joints with subsequent instability. I like to use the
analogy of a rubber band that is stretched out too much and no longer
holds the appropriate tension to function. The secondary stabilizers of
the ankle in this situation are two tendons on the outside of the ankle
called the peroneal tendons, which may also be inflamed (tendonitis) or
torn at the time of injury.
The big question is: why does one person get ankle instability after a
sprain while another does not? Ankle instability can occur after a single
major sprain or after a series of minor or major sprains. It is estimated
that there is some level of instability in anywhere between 5-30% of patients
sustaining a major ankle sprain. We believe this large variation to be
a result of multiple causes, such as due to variations in individual anatomy,
variations in ‘normal’ laxity (how flexible or stiff a patient
may be at baseline), severity of injury, alignment of the bones in the
foot, and many other factors. Additionally, the types of activities we
participate in (IE Basketball) as well as types of shoe-wear (IE high
heels or shoes that tilt us outwards) may predispose to an ankle sprain.
Some of these factors we can control and others we cannot.
Additionally, ankle instability tends to have a bimodal distribution, meaning
it presents in two different patient populations. In younger patients,
it may occur as a result of an injury to the ligaments and tendons. However
in some older patients, these ligaments and tendons may simply weaken
over time resulting in what I would term ‘secondary’ ankle
instability (not from a particular injury).
Importance of training and strengthening
As is the case with any activity, the more we adequately train our body,
the better it will function. Whether doing sudoku puzzles to improve our
cognitive brain function, or practicing free throws to prepare for an
upcoming basketball game, practice & training are critical to optimize
outcomes. This is especially true for maintaining ankle stability. In
truth, improvement of ankle stability is not only dependent on overall
ligament and muscle/tendon function, but also our brain function. There
is a term called proprioception, which is our mind’s awareness of
the body’s given location in space at any particular time. These
training regimens work both on the physical function of our ankles but
also the mental component as well.
Given that ankle instability can occur from an ankle injury or simply over
time as you age, performing an exercise regimen focusing on ankle stabilization
can potentially help avoid injuries and issues related to ankle instability.
Almost everyone will sustain some form of an ankle sprain in their life.
Incorporating an ankle stabilization program into your exercise regimen
may help avoid ankle injuries and subsequent development of ankle instability.
In the case of an ankle sprain, we know that we cannot make the ligaments
truly ‘normal’ again, however, these stabilization programs
are designed to strengthen the muscles and tendons around the ankle thereby
reducing the amount of work the ligaments have to do. This helps accelerate
a return to baseline activities as well as potentially decrease recurrent
injuries. This is evident in that there are improved outcomes with a functional
rehabilitation program of controlled support and simultaneous stimulation
of the ligaments and tendons compared to an extended period of cast immobilization
after an ankle sprain.
Exercises for Ankle Stability
The age-old adage of “If you don’t use it, you lose it”
is important to consider. Due to inactivity and changes in our lifestyles
as we age, our entire core, lower back, and lower extremities muscles
weaken over time. Therefore, prior to elaborating on specific exercises
for ankle instability, I try to emphasize the importance of incorporating
a consistent core and lower back program into a patients exercises regimen.
Specifically related to ankle stabilization, there are many different variations
of ankle stabilization exercises that can be done. When considering a
specific program, I try to take into account ease of access to equipment
in order to stay consistent with the program. Many of these can be performed
with minimal equipment, allowing patients to perform them at home, at
a local fitness center, or even while traveling.
I’d like to give recognition to a close friend and colleague of mine,
David Rivera, who is a physical therapist based out of Chicago, Illinois
as he has helped me develop this home program for my patients. For the
repetition exercises we generally recommend 3-4 sets of 10-15 reps approximately
2-4 times per week. For the balance exercises we recommend approximately
30 second intervals with 3-5 reps done on a daily basis.
Some of our favorites include:
4 way ankle strengthening with band: This can be done in the seated position or with the foot hanging off the
edge of the bed. Using a resistance band, the foot is taken through a
series of resisted motions. The resistance band needs to be adjusted based
on each of these motions in order to isolate dorsiflexion (upwards), plantarflexion
(downwards), inversion (inward), and eversion (outward). This can be accomplished
by either wrapping the resistance band around the opposite foot or around
a stationary object, such as the leg of a table.
Heel Raises (Single & Double Leg): We will often recommend performing these heel raises in a series of exercises
that progress through complexity. Patients should start on a flat surface
and using both feet to perform the heel raise. Next, a single leg heel
raise should be performed in similar fashion, alternating between sides.
Lastly, the double leg followed by single leg heel raise can be performed
with the heels hanging off the edge of a surface. The best way to do this
is using the lowest step on stairs. It is important to have a hand rail
or something to hold on to in order to help control the exercises and
protect from injury. These are termed ‘eccentric stretches’
as the calf muscle and Achilles tendon are allowed to stretch while simultaneously
contracting these muscles.
Single Leg Balance: The patient starts by standing with their feet at shoulder width, hands
placed on their hips, and then lifts one leg off the ground. The patient
focuses on maintaining head, chest, abdominal, and pelvic position without
allowing their pelvis, hips, or lower extremity to tilt. This can be done
initially on a stable surface such as a flat floor and for more advance
technique performed on a foam balance pad. Additionally for even more
complex training this can be done with the eyes closed, however this should
not be done until the more straightforward techniques are mastered.
Tandem Balance: This involves similar technique to the single leg balance however rather
than standing on a single leg, the technique is performed with one foot
in front of the other. It should be performed with one foot forward first
and repeated with the opposite foot in front in order to ensure equal
training on both sides. Similarly, it can be performed first on a stable
surface such as the floor followed by a more unstable surface such as
a foam pad. It should be performed first with the eyes open and for more
advanced training can be done with the eyes closed.
Tandem Squats: These involve performing a series of body weight squats (no actual extra
weight) focusing on proper technique. We will often have our patients
start with their feet at shoulder width and perform a controlled squat.
Once this is mastered, the feet can be brought closer together as the
more narrow base is harder to perform. Additionally, this is initially
performed on a stable surface such as the floor followed by a more unstable
surface such as a foam pad. It should be performed first with the eyes
open and for more advanced training can be done with the eyes closed.
Balance / Rocker Board: There are many variations of exercises using a balance board (sometimes
called a wobble board). Typically we will start with having the patient
simply stand with both feet equally apart and try to keep all edges of
the board from touching the ground. Next, the patients are instructed
to use their core, lower back muscles, and lower extremities to try to
guide the board in specific directions, with the goal of getting either
the front, back, or specific sides of the board to gently touch the ground
in a controlled fashion. As this is mastered, other activities can be
incorporated, such as placing a tennis ball in the center and trying to
keep it from moving or even incorporating various hand dexterity activities
while maintaining balance on the board.
Bosu Lunges: The bosu ball is a half-rounded rubber ball that is often available at
a fitness center. Similar to the balance board, there are many variations
of exercises that can be done based on expertise and function. Of note,
the basic exercises involve the use of the blue, half-rounded side of
the ball while more advanced maneuvers involve the flatter, black side.
However in most patients I recommend starting with relatively straightforward
The first exercise involves placing the front foot on the center of the
ball (designated by the rings on the ball) and the backfoot in the standard
lunge position. The patient then does approximately 10-15 lunges in this
position, focusing on a controlled and guided technique. The feet should
then be switched and this should be repeated for an additional 10-15 lunges.
The second exercise is slightly more difficult and involves placing the
back foot on the center of the ball and the front foot at an adequate
length to perform a lunge. Once positioned, 10-15 lunges should be performed,
again focusing on control of speed and position. The feet should again
be switched and this should be repeated for an additional 10-15 lunges.
For patients without a history of ankle instability, it is beneficial to
perform the exercises at three to four times a week incorporated into
an exercise regimen, however in patients with previous ankle sprains or
ankle instability it may be necessary to perform at least once a day,
if not multiple times throughout a day. Also, in our athletes, it is beneficial
to perform these exercises both before and after physical activities.
For all of these exercises, proper technique is key not only to optimize
outcomes but also prevent injury. Therefore, I will often refer patients
to at least one or two sessions of physical therapy so they can be taught
a home program to ensure safety and outcomes. Also, there are excellent
resources on-line and I often recommend patients use various publicly
available video media resources in order to learn the intricacies of these
exercises. Additionally, with all these exercises, the more basic exercises
should be focused on first and progression to the more complex techniques
should not be done until basic techniques are mastered. Lastly, if any
of these exercises are causing worsening or consistent pain, they should
be discontinued. As is the case with foot and ankle injuries or symptoms,
a medical professional should be consulted prior to implementing these programs.
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