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Posterior Ankle Impingement-Pathoanatomy, Evaluation and Administration

Prosterior Ankle


Posterior ankle impingement (PAI) is an umbrella time period for a group of pathologies that trigger posterior ankle ache with ankle plantarflexion (pointing the toes downwards). PAI mostly presents in athletes taking part in sports activities involving finish vary or compelled plantarflexion comparable to; ballet, soccer and cricket fast-bowlers.

Determine 1: Widespread examples of sports activities that require repetitive loaded ankle plantarflexion.

In these athletes, finish vary plantarflexion is painful and restricted attributable to impingement of soppy tissue or bony buildings between the bones in the back of the ankle.


The talocrural and subtalar joints are complicated buildings that depend on a number of passive (ligaments, joint capsules, and bony congruency) and dynamic (muscle tissues) helps for optimum stability and performance.

We are going to briefly dive into the precise anatomy of the buildings concerned in PAI right here:

Talocrural (ankle) joint

The talocrural joint (TCJ) consists of the distal fibula and tibia (shin), and the proximal (higher) floor of the talus. It’s a hinge joint, accountable for ankle dorsiflexion and plantarflexion (pointing toes up and down). The TCJ is lined with a skinny free capsule and is supported by many ligaments- of related curiosity are the posterior talofibular and posterior tibiotalar (forming the posterior side of the deltoid ligament) ligaments.

Determine 2: Bony anatomy of the talocrural joint.
Determine 3: The posterior tibiotalar and talofibular ligaments are potential sources of PAI

Talus and subtalar joint

The talus is located between the mortise (created by the distal tibia and fibula) and the calcaneus (heel) bone. Posteriorly, the talus options two tubercles- medial and trigonal processes. These type a groove that homes flexor hallucis longus (FHL), which is accountable for large toe flexion. The medial and trigonal processes can be implicated in bony PAI- these will probably be mentioned intimately later.

Determine 4: Posterior side of the talus and calcaneus. A: medial tubercle. B: groove for FHL. C: trigonal course of.

The articulation between the talus and calcaneus varieties the subtalar joint, which permits inversion and eversion of the rearfoot. It’s lined by a skinny, free synovial capsule.

Mechanisms of PAI

PAI could be categorised as bony or smooth tissue impingement. As you possibly can see in determine 4, many buildings could be compressed in the back of the ankle with finish vary plantarflexion. Right here we are going to check out essentially the most often seen causes of PAI- these can happen in isolation or together:

PAI Table

Desk 4: Doable smooth tissue and bony buildings that may be compressed within the house between the distal posterior tibia and posterosuperior side of the calcaneus.

Trigonal course of (Postero-lateral tubercle) of the talus

Variation of the trigonal strategy of the talus is the most typical reason for bony associated PAI signs.

Os trigonum is a small accent bone that varieties across the age of 8-13, and fuses with the trigonal course of by the age of 17 in roughly 80% of the inhabitants1. Within the different 20% it articulates with the talus by way of cartilage synchondrosis (related by hyaline cartilage). Os trigonum associated PAI is likened to a nut-cracker, whereby the ossicle turns into wedged between the posterior tibia, talus and calcaneus in the direction of finish of vary plantarflexion.

Trigonal course of fracture may result from acute trauma (compelled hyper-plantar flexion) or continual microtrauma, resulting in PAI. These may cause mechanical irritation of the encircling smooth tissues, additional contributing to signs. Lastly, an elongated posterolateral talar tubercle (generally known as a Stieda’s course of) can be implicated with PAI.

Determine 5: Presence of os trigonum on lateral X-ray.

Different much less widespread causes of PAI embody a outstanding calcaneal tuberosity, fracture of the posteromedial talar tubercle and different accent ossicles.

Delicate tissue causes

Flexor Hallucis Longus

FHL pathology is the most typical trigger of soppy tissue PAI1, and is often seen in ballet. The FHL is a deep muscle arising from the posterior floor of the fibula, coursing by the medial and trigonal processes of the talus and attaches to the plantar floor of the massive toe.

Tenosynovitis happens when the synovial sheath surrounding the tendon turns into irritated and infected with repetitive loading by massive ranges of movement. Tendinopathy happens when repetitive loading exceeds the tendon’s capability to adapt, leading to tendon thickening, ache and decreased elasticity.

It is very important be aware the presence of FHL pathology can happen in isolation with out PAI. Nonetheless, tendon adjustments related FHL pathology are often concerned with smooth tissue PAI.

Determine 6: Shifting from plie to pointe works FHL by full vary of movement

Ballerinas shifting out and in from a flat foot plie place to en pointe load the FHL muscle tendon complicated by excessive vary. Eccentric overload (e.g. touchdown jumps), weak calf musculature and extreme pronation can all enhance FHL loading. Presence of os trigonum may also compress and irritate the tendon2,3.

The related tendon and synovial sheath adjustments might cut back house in the back of the ankle and result in impingement.

Posterior capsuloligamentous and cartilage pathology

Scarring, thickening and irritation of the subtalar joint capsule can develop after acute trauma or repetitive overload. Equally, the cartilage lining the joint articulations can grow to be broken. These cartilaginous and capsular adjustments can grow to be impinged.

Laxity of the ATFL, one of many lateral stabilisers of the ankle joint, might allow extreme ahead translation of the talus on the tibia4. This permits the posterior floor of the talus to come back into nearer contact with the posterior lip of the tibia, thereby growing the chance of PAI.

Different much less widespread sources of PAI embody accent muscle tissues (e.g. peroneus quartus and flexor digitorum equipment longus), cysts and ganglions5.

Video abstract of PAI causes:



Athletes will current with posterior ankle ache deep to the Achilles tendon with plantarflexion. Signs worsen with actions that require repeated or loaded plantarflexion. It often presents in athletes that place or load their ankle into the extremes of this place, and is due to this fact unusual within the normal inhabitants.

Typical aggravating elements embody rising up onto toes, downhill operating6, slicing and alter of path, excessive heel footwear, and kicking in ball sports activities. Cricket fast-bowlers additionally place important masses by a comparatively plantarflexed lead plant foot when delivering.

Overuse vs continual PAI

Roughly half of PAI circumstances current as overuse accidents from repetitive microtrauma, and the opposite half stemming from acute traumatic accidents7.

Typical acute accidents embody lateral ankle sprains and compelled hyper-plantarflexion.

After acute ankle damage, signs could be delayed and infrequently take as much as 3-4 weeks6 to manifest, often very step by step. This may be attributed to the early inflammatory response that causes localised ache and swelling, limiting ankle ROM. As soon as this settles and plantarflexion vary of movement improves, the ensuing smooth tissue or bony pathology turns into symptomatic.

Overuse accidents might stem from:

  • Repetitive loading of the ankle leading to cartilage defects, ligament laxity, capsule synovitis and degenerative adjustments.
  • Load exceeding FHL tendon capability leading to tenosynovitis and tendinopathic adjustments.

Subjective findings to pay attention carefully for embody:

  • Will increase in coaching load (particularly pointe or leaping work in ballet)
  • Particular mechanism of damage involving loaded or excessive plantarflexion
  • Earlier historical past of ankle joint/FHL damage or continual ankle instability
  • Ache with actions requiring finish vary plantarflexion
  • Restricted motion into plantarflexion

Goal examination


Relying on the character and chronicity of PAI, swelling could also be noticed.

Swelling on the medial side of the ankle joint, slightly below the medial malleolus can counsel FHL involvement, which must be differentiated from different pathologies. Ligamentous damage and subtalar synovitis may additionally contribute to posterior ankle swelling.

Assessing arch top is vital as it may be a contributory consider PAI.

Pes cavus (excessive inflexible arch) toes have poor shock absorption when planting the foot, predisposing athletes to bony or joint associated PAI.

Conversely, pes planus (flat) toes require better contribution from the musculature (comparable to FHL and tibialis posterior) and ligaments (e.g. spring ligament) to take care of the arch. These foot varieties make athletes extra prone to smooth tissue variations of PAI, particularly FHL tenosynovitis.

Purposeful evaluation

Cautious evaluation of plantarflexion and aggravating motion patterns are vital concerns for each an correct prognosis and administration. Ballet dancers with restricted plantarflexion vary might invert on the heel to compensate for decreased top when shifting into pointe place. There could be elevated rotary forces and pressure on posterior ankle buildings throughout turnout attributable to lack of hip exterior rotation8. Due to this fact, hip exterior rotation power and vary ought to be assessed in dancers presenting with PAI. Quick bowlers that overstride on their plant foot enhance ankle and subtalar joint loading.

Determine 7: Inverting on the rearfoot in an try to extend top can enhance pressure on ankle buildings and predispose dancers to PAI.

Power testing

Insufficient power of the triceps surae complicated (gastrocnemius and soleus) and intrinsic foot muscle tissues (comparable to flexor hallucis brevis, adductor and abductor hallucis) can overload the FHL. Athletes ought to have the ability to carry out not less than 20 single leg calf raises with good form- this implies sustaining a straight knee, protecting the midline of the shin in keeping with the twond metatarsal, no rocking forwards for momentum, clean managed actions at a velocity of 1 second up- 1 second down by full vary of movement. Sue Mayes, precept physiotherapist for the Australian ballet firm discovered that dancers with <25 single leg heel raises had been extra prone to report ankle ache within the earlier 6 months, and had a considerable decline in time-loss ankle accidents after a SLHR coaching program.

Sound intrinsic foot muscle management is particularly vital for ballet dancers. These muscle tissues help in flexing the massive toe (and don’t cross the ankle joint)- offloading the overworked FHL throughout pointe work or leaping/touchdown.  In addition they assist shield and stabilise the arch of the foot, lowering the chance of different ankle accidents.

Determine 8: The Australian Ballet Firm’s information to performing single leg heel raises with good method


Maximal ache and tenderness is felt deep to the Achilles tendon and could also be barely medial or lateral. FHL tenosynovitis is often accompanied by palpable swelling and crepitus (which could be auscultated on a stethoscope) over the medial side of the ankle.

Posterior impingement take a look at with overpressure

This take a look at includes inserting the ankle joint into maximal plantarflexion with the affected person in susceptible. Overpressure with inversion/eversion bias could be utilized for much less irritable sufferers. It’s generally accepted because the definitive take a look at for PAI though there may be restricted proof on its specificity or sensitivity.


Vary of movement

Energetic and passive plantarflexion vary of movement will probably be typically painful in PAI. Speedy, repeated or compelled plantarflexion are prone to reproduce signs in much less irritable athletes. Dancers with restricted ankle plantarflexion vary of movement usually tend to compensate by inverting on the heel to realize elevated top. This will increase the chance of inversion damage, FHL overuse and PAI.

Ankle dorsiflexion and 1st MTP extension vary of movement will help establish related muscle tightness and joint hypomobility. This will alter joint biomechanics throughout sport actions, predisposing athletes to PAI.

Integrity of the ATFL could be assessed utilizing the anterior drawer take a look at. This ought to be thought-about in athletes with a earlier historical past of ankle sprain as a result of extreme anterior motion on the talus can result in PAI (outlined beneath Posterior capsuloligamentous and cartilage pathology).

FHL testing

Resisted large toe flexion is an efficient method of isolating the FHL to display for weak spot and pathology. A variation of this take a look at particular to FHL’s perform includes simultaneous resisted large toe flexion and ankle plantarflexion by full vary of movement. Flexing and increasing the massive toe might reproduce crepitus alongside the tendon sheath.

Differential diagnoses

There are various buildings that may trigger ache in the back of the ankle, which makes differential prognosis vital for administration and return to sport.

Remoted FHL tendinopathy

Athletes with remoted FHL tendinopathy will sometimes have extra ache touchdown from jumps in comparison with PAI, and shouldn’t have any ache on posterior impingement testing/ maximal passive plantarflexion.

Achilles tendinopathy

These will probably be tender immediately over (relatively than deep to) the mid portion or insertion of the Achilles on the calcaneum. Achilles tendinopathy is related to morning stiffness, heat up phenomenon, and aggravated deep stretching into dorsiflexion (particularly insertional AT), setting it aside from PAI. They won’t have a constructive posterior impingement take a look at.

Peroneal tendinopathy

This may be simply differentiated with ache, weak spot or sublaxation on resisted dorsiflexion and eversion in addition to cautious palpation over the tendon.

Tarsal tunnel syndrome

Entrapment of the posterior tibial nerve within the tarsal tunnel will trigger burning, tingling or numbness on the medial side of the ankle and plantar foot. Roughly half of circumstances are idiopathic, nonetheless, it could come up after important ankle trauma comparable to an inversion sprain. Sensory adjustments and a constructive Tinel’s take a look at (tapping the posterior tibial nerve) to elicit signs differentiates it from PAI.

Lumbar backbone radiculopathy

Radicular ache from the lumbar backbone is a much less probably reason for posterior ankle ache and could be simply differentiated with a neurodynamic testing that tensions the concerned nerves (constructive straight leg increase or droop take a look at). Equally, sural nerve pathology could be differentiated with a straight leg increase with inversion bias to particularly pressure the nerve. PAI athletes will take a look at negatively and have full lumbar vary of movement.

Posterior tibial tendon pathology

These will current with medial ankle ache, just like FHL pathology. Maximal tenderness is usually simply behind and beneath the medial malleolus. They may have ache on resisted inversion, nonetheless, shouldn’t have any signs with resisted large toe flexion or passive large toe flexion and extension.


Commonplace X-rays are most frequently used as the primary line investigation to distinguish between bony and smooth tissue related PAI. Lateral views will typically choose up an enlarged postero-lateral talar tubercle (Stieda course of), os trigonum, osteophytes or free our bodies. Current research have discovered that rotating the ankle into 25degrees of exterior rotation6 offers higher diagnostic accuracy for bony abnormalities of the posterior talus.

CT scans present better element in respect to the dimensions, quantity and placement of bony lesions comparable to avulsion fractures.

MRI is the popular methodology of imaging for evaluating smooth tissues comparable to FHL, accent muscle tissues, cartilage lesions, bone marrow oedema, joint effusion and synovitis.


Video abstract of administration

First line administration of PAI ought to be conservative and embody:

1. A interval of modified workload avoiding provocative finish vary plantarflexion to assist settle signs and any current swelling. The length will largely rely on the irritability and nature of signs. This time is a superb alternative for athletes to cross-train and work on elements contributing to their PAI. For instance, engaged on method, hip exterior rotator and foot intrinsic power in ballet. Area sport athletes could possibly proceed operating, nonetheless, ought to keep away from change of path or tackling or kicking. Power and conditioning work could be continued within the health club with applicable modification to keep away from provocative positions- actions comparable to biking and most above the knee strengthening workouts ought to be tolerated.
Of fast be aware, athletes with tolerable signs that want to proceed their season can keep coaching quantity. Nonetheless, it’s probably they may require a interval of longer relaxation on the completion of the season. Elite athletes might go for localised ultrasound guided corticosteroid injection to scale back swelling and ache. A lateral method is often carried out to keep away from the medial neurovascular bundle.

2. A brief course of NSAIDs to scale back ache and swelling related to PAI.

3. Mobilisation workouts or guide remedy if indicated within the goal examination. Examples could also be mild distraction and mobilisation (warning with acute subtalar joint damage) of the talocrural and subtalar joints to optimise load distribution throughout plantarflexion. Massive toe mobilisation and smooth tissue launch of tight calf musculature could be carried out if there are ROM deficits on testing.

4. Gradual return to exercise and loading by plantarflexion vary as soon as signs have settled. Centered strengthening of calf and foot intrinsic muscle tissues are vital for optimum loading and biomechanics on the ankle joint. It’s going to assist offload sometimes overworked muscle tissues comparable to FHL and tibialis posterior.
The flexor hallucis brevis is of significance because it helps stabilise the massive toe throughout push off and touchdown jumps. Deficits in FHB power ends in these propulsive and affect forces being distributed to different tissues within the foot, ankle and calf.
Guaranteeing correct method with calf raises (as outlined in power testing) is essential for all weight-bearing athletes. Step by step progress vary, guaranteeing that athletes tolerate signs throughout and after train.

The next offers a normal information to progressing workouts into an athlete’s coaching program.

Foot intrinsic and ankle stability workouts ought to be included early within the rehab progress and continued regularly:

  • Toe yoga
  • Brief foot and resisted toe flexion (Theraband) with hip hinge
  • Towel scrunches
  • TheraBand large toe flexion (FHL)
  • TheraBand inversion
  • TheraBand eversion
  • Stability board/ Mobo board/ unstable floor (add hip hinge, higher physique actions)
  • Y stability take a look at protocol
  • Tibialis anterior strengthening for quick bowlers can be vital to assist eccentrically management fast plantarflexion within the lead leg.

Gradual loading into plantarflexion ought to be carried out as soon as signs have settled. Emphasis ought to be on single leg workouts to stop ‘dishonest’ with the unaffected facet. Keep away from ‘locking the ankle out’ at finish vary plantarflexion- as an alternative concentrate on clean and managed recruitment of calf musculature, minimising extreme inversion with easy heel raises. Carry out workouts from this stage onwards each different day, choosing the best resistance attainable while guaranteeing sound method.

As soon as the athlete is ready to obtain >20single leg heel raises with sound method and no enhance in signs, they’re able to progress to extra sport particular workouts. These be step by step launched, monitoring signs carefully, and be carried out contemporary. Progress from double to single leg, then add exterior load as required. Particular emphasis ought to be on controlling landings and sustaining good trunk management.

  • Stair climbing/bounding (progress to a number of stairs at a time)
  • Skipping (progress to facet to facet)
  • Single leg squats on slant board
  • Vertical soar
  • Broad soar
  • Bounding drills
  • Pogo jumps
  • Lateral hop and stick
  • Reformer leaping
  • Hurdles (forwards and lateral)
  • Wall acceleration drills

5. Return to sport ought to be guided by medical findings and is variable between totally different athletes. Usually, soccer gamers have shorter return to play timeframes than ballet because of the period of time spend en pointe, leaping and touchdown. It might take 4-6 weeks to return to play in much less irritable circumstances, and round 4 months for dancers to return to full efficiency8.
In athletes comparable to quick bowlers and soccer gamers, the posterior impingement take a look at and beforehand provocative actions ought to be pain-free.
Decrease limb power and mobility asymmetries ought to have been addressed within the earlier phases. There ought to be a gradual construct up in coaching quantity e.g. variety of bowling deliveries, time spent on the soccer area, quantity of leaping and touchdown within the dance studio.

Small research have proven that conservative therapy alone has good prognostic outcomes, with as much as two-thirds of circumstances resolving9.

When conservative administration fails to alleviate signs after 12 weeks, surgical procedure is warranted. This may occasionally contain excising the problematic bony buildings (e.g. os trigonum) and accent muscle tissues, or releasing hypertrophic scar tissue and the FHL tendon sheath. Particular consideration ought to be thought-about with os trigonum excision as it’s a weightbearing construction when the ankle is in full plantarflexion. Removing will end in better strain on the floor of the talus attributable to a discount in floor space accessible for articulation. This will predispose athletes to subtalar joint osteoarthritis over time.

There was a shift away from open surgical procedure in the direction of a much less invasive endoscopic method attributable to quicker restoration occasions, and decreased problems10. Problems from surgical procedure embody an infection, harm to the medial neurovascular bundle (utilizing a posteromedial method) and sural nerve (posterolateral method). Surgical procedure yields superb outcomes, with research reporting success charges of round 80%11. Return to play following endoscopic surgical procedure is just like conservative timeframes, nonetheless, most research solely checked out skilled athletes.


PAI often presents in athletes that repetitively load their ankle joint in plantarflexion. Quite a few buildings in the back of the ankle can contribute to symptoms- these could be bony or smooth tissues. The presence of os trigonum and FHL tenosynovitis are the most typical options of PAI. Cautious evaluation is required to find out the reason for signs and differentiate PAI from different pathologies. Most circumstances of PAI could be managed conservatively with a interval of offloading, anti-inflammatories, and focused strengthening workouts. Surgical procedure is warranted after unsuccessful conservative administration and has beneficial outcomes.

Julian Tubman

Julian Tubman (APAM)

Featured within the High 50 Bodily Remedy Weblog


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