1. Introduction / Plain Theory

Flat feet (or pes planus) describe a reduction or collapse of the medial longitudinal arch of the foot, causing the inner side of the foot to come closer to the ground.
When the foot rolls inward excessively during walking or running, this is known as overpronation.

Both conditions can be structural (present from birth) or functional (developing over time due to muscular imbalance, ligament laxity, or altered load mechanics).

Flat feet are common and not always problematic.
However, when arch collapse alters the natural shock absorption or alignment of the lower limb, it can contribute to pain or dysfunction in the feet, ankles, knees, hips, and lower back.

2. Typical Symptoms and Functional Impact

• Flattened or low foot arches, sometimes visible asymmetry between sides.

• Pain or fatigue in the arches, heels, or ankles after standing or walking.

• Pain radiating to the knees, hips, or lower back due to altered mechanics.

• Uneven shoe wear (inner edges wearing faster).

• Stiffness or reduced foot spring when walking.

Functional impact:
Flat feet can reduce walking efficiency, shock absorption, and stability.
Over time, this may lead to compensatory strain along the kinetic chain — from plantar fasciitis and Achilles tendinopathy to knee and pelvic pain.

Red flags:
Sudden loss of arch height, swelling, or severe pain may indicate posterior tibial tendon dysfunction or fracture and should be medically assessed.

3. Contributing Factors / Underlying Causes

• Genetic predisposition or ligamentous laxity.

• Muscle weakness in intrinsic foot and calf stabilisers.

• Prolonged standing or poor footwear with inadequate support.

• Previous ankle sprain or Achilles tightness.

• Obesity or rapid weight gain.

• Pelvic or hip asymmetry, affecting lower-limb alignment.

• Sedentary lifestyle leading to deconditioning of postural muscles.

From an osteopathic perspective, flat feet and overpronation reflect systemic postural adaptations, not just local foot collapse.
Treatment focuses on optimising movement efficiency and balance across the entire lower limb and spine, rather than rigidly “correcting” the foot shape.

4. Osteopathic Approach

Osteopathic care aims to improve foot mechanics, enhance support function, and rebalance load transmission through the kinetic chain.

An osteopathic assessment may include:

• Observation of posture, gait, and foot arch dynamics during walking.

• Palpation of fascial tension and joint mobility in the foot and ankle.

• Mobilisation of the subtalar, midfoot, and ankle joints to improve motion.

• Myofascial release for the plantar fascia, calves, and tibialis posterior.

• Functional and indirect techniques to enhance proprioception and circulation.

• Mobilisation of the knees, hips, and pelvis to ensure balanced load distribution.

• Guidance on footwear, orthotic use (if indicated), and strengthening exercises for arch support.

The focus is on functional improvement and adaptability, not just structural correction.

5. Scientific Evidence & References

Research supports a multifactorial approach to managing flat feet and overpronation — including manual therapy, strengthening, and proprioceptive training.
Evidence shows that addressing proximal mechanics (hip and core control) can reduce symptoms and improve alignment.

Osteopathic treatment complements these approaches by integrating biomechanical, fascial, and postural assessment into care.

References

1. Buldt AK, Menz HB. Incorrectly labelled “flat feet”: redefining the functional role of foot pronation. Br J Sports Med. 2018;52(3):155–156.

2. Franettovich Smith MM, et al. Foot kinematics in people with and without functional flat foot: a systematic review and meta-analysis. J Foot Ankle Res. 2014;7(1):50.

3. Franettovich Smith MM, et al. Effectiveness of foot strengthening exercises in reducing pronation and improving function. BMJ Open Sport Exerc Med. 2017;3(1):e000291.

4. Chuter VH, et al. Foot posture, pronation, and load transfer: clinical correlations in musculoskeletal pain. Gait Posture. 2014;40(4):689–694.

5. Tozzi P. A unifying neuro-fasciagenic model of somatic dysfunction — underlying mechanisms and treatment. J Bodyw Mov Ther. 2015;19(2):254–265.

6. Degenhardt BF, Johnson JC, Fossum C, et al. Osteopathic manipulative treatment for foot posture and function: pragmatic pilot study. J Bodyw Mov Ther. 2017;21(4):857–865.

7. Zhang X, et al. Manual therapy and exercise for flexible flatfoot: a systematic review and meta-analysis. Clin Rehabil. 2022;36(7):874–887.

8. Xie Y, Chen Z, Yang Z, et al. Comparative efficacy of manual therapy interventions for overpronation and foot dysfunction: network meta-analysis. Front Pain Res. 2024;15:1507535.