How Joint Hypermobility Affects Your Feet
Joint hypermobility means your joints move beyond the normal range of motion. While some people with hypermobile joints experience no problems at all, for many others, the excessive flexibility creates real issues — particularly in the feet and ankles.
Your feet contain 33 joints each and bear your entire body weight with every step. When the connective tissue holding those joints together is looser than normal, the mechanical consequences can be significant.
Research shows that two-thirds or more of adults with hypermobile Ehlers-Danlos Syndrome (hEDS) have ankle and foot involvement. Similar patterns are seen in people with Hypermobility Spectrum Disorder (HSD) and generalised joint hypermobility.
The Biomechanical Cascade: From Lax Tissue to Foot Pain
Understanding why hypermobility causes foot problems starts with understanding the chain reaction it sets off:
Lax connective tissue — In hypermobility, the collagen in your ligaments and tendons is stretchier than normal. This affects every structure in the foot that relies on connective tissue for support.
Tibialis posterior insufficiency — The tibialis posterior muscle and tendon is the primary supporter of your medial longitudinal arch (the main arch on the inside of your foot). When the connective tissue is lax, this tendon can't maintain the arch effectively under body weight.
Arch collapse and excessive pronation — Without adequate arch support from the tibialis posterior, the foot collapses inward. This excessive pronation changes the alignment of every joint above and below.
First ray hypermobility — The first metatarsal (the long bone behind your big toe) becomes unstable, contributing to bunion formation and reducing the foot's ability to push off effectively during walking.
Altered gait mechanics — A 2020 study by Veer and colleagues confirmed that people with hEDS and HSD show measurably altered foot and ankle movement patterns during walking, with changes throughout multiple segments of the foot.
Conditions Caused or Worsened by Foot Hypermobility
The biomechanical changes from hypermobility contribute to a range of conditions that we regularly treat at Foot Health Clinic:
Flat feet (pes planus) — The most visible sign of foot hypermobility. The arch collapses under load, and the foot rolls inward excessively. In hypermobile individuals, this isn't simply a structural variant — it's a functional problem that affects the entire lower limb chain.
Plantar fasciitis — The plantar fascia is placed under greater strain when the arch collapses. Hypermobile patients are more prone to developing this painful heel and arch condition, and it can be more persistent due to the underlying joint laxity.
Posterior tibial tendon dysfunction (PTTD) — The tibialis posterior tendon is overworked in hypermobile feet as it struggles to maintain the arch. Over time, this can lead to tendon degeneration, pain along the inner ankle, and progressive flatfoot.
Ankle instability and recurrent sprains — Lax ankle ligaments make the joint less stable, increasing the risk of rolling the ankle. Many hypermobile people report frequent sprains or a persistent feeling that their ankle might "give way."
Bunions (hallux valgus) — First ray hypermobility is a recognised contributing factor in bunion development. The unstable first metatarsal drifts outward while the big toe angles inward, creating the characteristic bony bump.
Achilles tendonitis — Altered foot mechanics change how force is transmitted through the Achilles tendon, increasing the risk of overuse injury.
Metatarsalgia — Pain under the ball of the foot, often caused by altered weight distribution when the arch collapses and the forefoot is forced to absorb more load than it should.
Compensatory toe clawing — When the foot is unstable, the small muscles of the toes work overtime to grip the ground for stability, leading to curled or clawed toes over time.
Assessing Foot and Ankle Hypermobility: The FAFI
The Beighton Score is the standard screening tool for generalised joint hypermobility, but it doesn't test a single joint below the knee. This is a significant gap when the foot contains 33 joints and the ankle complex is one of the most commonly affected areas.
The Foot and Ankle Flexibility Index (FAFI) was developed specifically to fill this gap. It's a 6-item clinical test that assesses ankle dorsiflexion range, ankle anterior draw, subtalar inversion, midtarsal inversion, midtarsal abduction and adduction, and first MPJ dorsiflexion. A score of 4 or more out of 6 indicates foot and ankle hypermobility, with a sensitivity of 95% and specificity of 86%.
At Foot Health Clinic Samford, we use both the Beighton Score and the FAFI as part of our hypermobility assessments. This combined approach means we can identify patients whose foot hypermobility would be completely missed by general screening alone — and there are many of them.
The Injury Risk: What the Research Shows
Hypermobility doesn't just affect the feet — it increases injury risk throughout the lower limb. A systematic review with meta-analysis found that people with generalised joint hypermobility have a 4.7 times greater risk of knee injury during contact sporting activities. Generalised joint hypermobility is also recognised as a risk factor for ACL (anterior cruciate ligament) injury, particularly in males.
Beyond acute injuries, a prospective cohort study found that joint hypermobility during adolescence is a risk factor for developing chronic musculoskeletal pain. This means early identification and management of hypermobility-related foot issues may help prevent a cycle of pain and dysfunction in the longer term.
How Podiatry Treatment Helps Hypermobile Feet
The good news is that hypermobility-related foot problems respond well to targeted podiatry treatment. The aim isn't to "fix" the hypermobility — the connective tissue will always be more elastic. Instead, we provide the external support and strengthening that the lax tissue cannot.
Custom orthotic therapy — Orthotics are a cornerstone of managing hypermobile feet. A study on children and adolescents with generalised joint hypermobility and lower limb pain found that custom orthotics reduced pain by an average of 27 points on a 100-point scale, improved quality of life, and increased functional capacity (walking endurance improved by 27 metres on the six-minute walk test). These improvements were maintained at three months. A separate pilot study on adults with EDS found custom foot orthoses improved pain, fatigue, and mental health-related quality of life over three months.
Custom orthotics work by providing the structural support that lax connective tissue cannot, improving proprioception (your body's awareness of joint position), reducing excessive pronation, and taking strain off the posterior tibial tendon and plantar fascia.
Physical therapy — At Foot Health Clinic, we have Thor laser therapy, shockwave treatment, and expert mobilisation techniques available to address the painful conditions that arise from hypermobility. These modalities can be effective for managing plantar fasciitis, Achilles tendonitis, and other soft tissue conditions in hypermobile patients.
Strengthening and exercise programs — Targeted exercises to strengthen the intrinsic foot muscles, improve ankle stability, and enhance proprioception are an essential part of long-term management. Strong muscles help compensate for lax ligaments.
Gait analysis — Understanding exactly how your feet move during walking helps us design the most effective treatment plan. We use video gait analysis to identify the specific movement patterns contributing to your symptoms.
Getting Help at Foot Health Clinic Samford
If you have hypermobility and are experiencing foot or lower limb pain, a thorough podiatry assessment is the first step toward effective management. We see patients of all ages — from children whose hypermobility is affecting their development and participation in sport, to adults managing chronic pain and instability.
Our assessment includes Beighton Score screening, the Foot and Ankle Flexibility Index (FAFI) for foot-specific hypermobility, Foot Posture Index scoring, navicular drop measurement, muscle strength testing, and gait analysis to build a complete picture of how hypermobility is affecting your feet and lower limbs.
Book your appointment at Foot Health Clinic Samford — call (07) 3289 6050 or book online.