Running Injury Prevention: Ankle Stabilizers
The ankle joint: a commonly injured area of the runner and athlete. Whether it be ankle sprains, ankle laxity, calf problems, posterior tibialis problems, peroneal tendinitis (most of the time tendinosis by the time I see people). A problem I have is that people seem to think the foot is one joint. Most patients that come to me refer to any pain in the foot as ankle pain. In fact, the foot is extremely complicated because it is composed of so many joints! The complexity of the foot rivals the hand given the number of intrinsic muscles, joint interactions and lack of consensus on many aspects of biomechanics and muscle function in the research world. Let's take a look at the true area of the ankle and try to look a little deeper into what it is, how it functions and considerations that need to be made for good function!
The ankle joint: a commonly injured area of the runner and athlete. Whether it be ankle sprains, ankle laxity, calf problems, posterior tibialis problems, peroneal tendinitis (most of the time tendinosis by the time I see people). A problem I have is that people seem to think the foot is one joint. Most patients that come to me refer to any pain in the foot as ankle pain. In fact, the foot is extremely complicated because it is composed of so many joints! The complexity of the foot rivals the hand given the number of intrinsic muscles, joint interactions and lack of consensus on many aspects of biomechanics and muscle function in the research world. Let's take a look at the true area of the ankle and try to look a little deeper into what it is, how it functions and considerations that need to be made for good function!
Image from www.deansomerset.com
The
ankle “joint” that many individuals usually refer to is usually the
talocrural joint. However, the ankle is actually made up of many
different joints. The talocrural joint is where most
dorsiflexion/plantarflexion originates from and consists of the
connection between the tiba, fibula and talus (bone above the
calcaneus/heel bone). Right below that we have the subtalar joint,
which is the connection between the talus and calcaneus. The
subtalar joint is where a great deal of ankle inversion/eversion comes from. The
talonavicular joint is next, consistenting of the talus and navicular
bone, a common point and contributor to dropped foot arches via the posterior tibialis (note, as
we are discussing the ankle “joint”, I will save the remainder of
the foot, midfoot, forefoot joints for another point. However they
are equally important and connected). Then we have calcaneocuboid
joint, which is the connection of the calcaneus (heel bone) and the
cuboid (first lateral tarsal bone) that along with the talonavicular
joint makes up the transverse tarsal joint.
These
joints are controlled and pulled in many directions by many muscles.
Ankle stability wise the first muscles that come to mind are the
anterior tibilais, posterior tibialis, and peroneal muscles. While
the intrinsic muscles, including the muscles of the hallux (big toe),
toe extensors/flexors and more in the mid and forefoot are important,
we are going to focus on the major ankle stabilizer muscles (the flexor and extensor digitorum muscles do play roles ankle plantarflexion and influence the talocrural joint and subtalar joints but I will address that in another post). The
tibialis muscles are the larger muscles that control the medial side
of the ankle. The anterior tibialis inserts onto the first cuneiform and proximal aspect of the first metarsal bone. Although it has connection points in the midfoot, the passage of the tendon through the medial ankle compartment provides a strong pull there. The posterior tibialis inserts onto the navicular bone, medial cuneiform and a few other aspects of the medial bone structure (there are superficial and deep components of the distal connection of the posterior tibialis tendon) and assists aspects of the plantar fascia with holding up the medial longitudinal arch. Both of these muscles function as invertors and help control the inward roll of the foot eccentrically during loading response/landing. The posterior tibialis also plays a major function in re-supinating and stabilizing the ankle joint during the propulsive phase. This is extremely important for creating a stable base for the gastrocsoleus complex to effectively plantarflex the ankle (and push you forward). The anterior tibialis is more important during the swing phase of gait for helping get the foot back into dorsiflexion so the toes can clear the ground and prepare for initial contact. Despite the anterior tibialis functioning as a dorsiflexor and the posterior tibialis as a plantarflexor, they must work synergistically to maintain control and integrity of the medial longitudinal arch via holding up the navicular, cuneiform, proximal 1st metarasal, which thus keeps the calcaneus, talar and navicular joints under control. While I do want to focus primarily on the muscles that attach near the ankle joint, I have to comment that the posterior tibialis works strongly with the flexor hallucis (great toe) longus and flexor digitorum (rest of the toes) longus to supinate and plantarflex the foot during toe-off and the propulsive phase of running and walking gait.
The peroneus longus, brevis and tertius make up the lateral ankle stabilizers and primary ankle evertors. The brevis and longus both work strongly over the subtalar joint and thus are important to pronatory and supinatory (is that a word?) motion. The amazing peroneus longus starts on the lateral fibular head, travels on the lateral side of the foot, drops under the foot and goes all the way to the base of the first metatarsal. This muscle functions to both evert the foot and more importantly keep the distal aspect of the first metatarsal down. In conjunction with the anterior tibialis, this muscle also functions to stabilize the 1st metatarsal, thus helping to stabilize a large portion of the medial longitudinal arch. The peroneus brevis, due to the tendon running behind the lateral melleolus, is also a plantar flexor and evertor of the ankle (like the longus). It's connection to the proximal aspect of the 5th metarsal creates more action on the lateral aspect of the foot than the longus (which has a greater lateral pull on the medial foot). The peroneus tertius is the only dorsiflexor of the group, as it passes in front of the lateral malleolus and connects to a similar spot to the peroneus brevis.
My left hip allows less active motion to compensate and provide stability for my weak left ankle.
With stabilization, you need to make sure the medial and lateral forces are equal. Those individuals who land in a highly supinated position while running tend to have fairly strong ankle invertors (posterior tib, anterior tib, etc) while they have weak ankle evetors (you may see excessive wear on the lateral side of their shoes). This places them at high risk for lateral ankle sprains. Those who tend to pronate heavily tend to have weaker and lengthened ankle invertors with tight or strong ankle evertors. The best you can do to reduce injury risk is to try to balance them out strength wise. Even if an individual lands very supinated (then pronates inward upon landing) and has good control of the ankle invertors, the peronus longus needs to be strong to keep the first metarsal down on the ground and create a stable transverse metarsal arch (There are several functional arches in the foot). That is just one example of how these muscles work synergistically for multiple purposes.
If
you have excessive mobility, strength and stabilization are what you
need. If you lack ankle/foot mobility, mobility and strength through
the ROM are what you need. Ankle instablity is pretty
self-explanatory. The stiffness part is different. Those with stiff
ankle joints (not muscle stiffness) will have a difficult time
loading forces appropriately at the the ankle. This can lead to
loading forces being compensated for and taken up by the joints above
and/or below (knee, midfoot, forefoot). As I have stated many times
before, balance, both in strength and loading, is important for
injury prevention. So an individual with stiffness will first need
to work on mobility before trying any strengthening exercises as they
need to attain full motion. If you strengthen while in a limited
motion, that tends to make the muscles tighten down more, leading to
stiffer joints. Ankle mobility will be discussed in another post.
Before
I go off on another tangent, let's talk about some of the many ankle
exercises I like for stabilization. As many of these are stabilization exercises (as well as strength), I usually have my patients do these as repeated motions with 2-3 second holds (progressing to 6-10 seconds) or in the case of the Short Foot exercise longer >30 second holds with dynamic motions.
Windshield
Wipers
Medial Windshield Wipers
This
is a great exercise that seems to be really good at bringing in the
medial and lateral stabilizers of the arch as it has a heavy
transverse plane motion component. The medial version nicely pulls the anterior tibialis, posterior tibialis together to adduct the foot away from the typical collapsed posture most people have. The additional weight bearing through the ground during the pull (if done with a towel) is a great way to also pull the proximal intrinsic foot muscles in to function. For the lateral version, this pulls all three evertors in, especially the longus as you should push through the ground with the base of the first metarasal. The lateral version is a great exercise to even out those individuals who tend to land in a heavily supinated position (the people who chew up and destroy the lateral edges of their shoes). Place the band or towel at the 1st or 5th toe joint depending on the direction and pull!
Lateral Windshield Wipers
Janda
Short Foot Exercise
This
is a classic exercise that many would deem more “functional.” Dr. Vladimir Janda was a fantastic neurologist who set the grounds for
many movement professionals years ago by studying movement
disorders and trying to understand their root cause. The short foot
exercise digs deeper at the true function of the arch as it is
involved in all three planes of motion. The medial longitudinal
arch of the foot lengthens and shortens far more than it truly drops or lifts as most people seem to think (although I will continue to use that terminology for the sake of public understanding). The point of the short
foot exercise is to functionally train all the muscles mentioned above in supinatory motion, rather than simply eversion or inversion. This exercise should be performed by pulling with the posterior/anterior tibialis along with pulling the base of the 1st metarasal posterior or backwards toward the heel. Do not use your toe flexors to pull back as that is a compensation and utilizes the flexor digitorum longus far more than others. The cue I usually use is placing something under the base of the 1st metatarsal and having my patients pull that posterior toward the heel without their toes. This exercise should start out in sitting, progress to standing and eventually can be done during single leg balance (both static and dynamic training).
Single
Leg Balance Neutral Arch
Apologies for the black toenail... An accident that happened during plyometric exercise experimentation...
Want
to be able to hold a neutral arch while you walk and run? Well you
need to practice just standing first. Once you have the basic
strength from the above exercises, progression and functional
practice are needed. I usually have my patients perform the short
foot exercise in standing while on one leg, trying to teach them how
to control the foot and hold it in a neutral position (not collapsed or overly supinated). Once you can hold this for 30-60 seconds, progressions can include doing this with your eyes closed (proprioceptive training), performing single leg squats, hops, jumps etc. The goal is to reintroduce sport specific activities while still focusing on control and stabilization on the ankle. So be creative.
Maybe if I work on the stabilization of my left ankle, I'll be able to catch Matt Crowe (far right, winner of the 2017 Jackie Bristow 5k and fast runner. Look for him on the track soon!)
Although
this post has focused on the ankle, I need to make it clear that the
entire limb needs to be assessed to understand why or where a certain
movement (or lack thereof) may be coming from. My question for my patients is always
how did this start in the first place? Was because of joint
stiffness elsewhere and the ankle took up the additional load? Was
it just muscle weakness or lack of use from a certain repeated motor
patterns? Is this motion a response or compensation for another joint
somewhere else? As per usual, with lower extremity issues, the hip
is a good place to check as it is a major proximal stabilizer (or at
least is supposed to be) for the lower extremity. Stiffness, joint
gliding issues or issues with the screw-home mechanism (locking and
unlocking) of the knee are also things that can contribute to the
ankle taking up additional forces or stiffening. So don't just take these
exercises and believe they will cure everything. Ever person and
patient is unique, with signature movement patterns, weaknesses,
strengths and deficits. So assess yourself or others as such.
Thanks
for joining me on my journey farther down the rabbit hole. It will
only get more interesting from here. Get out there and keep building that running body!
Thanks for reading and don't forget to tack on!
-Dr. Matthew Klein, PT, DPT