Can Pes Planus Be Caused by Marching, Rucking, and Running?
Yes, repetitive high-impact activities like marching, rucking, and running can contribute to the development of acquired pes planus in adults, primarily through posterior tibial tendon dysfunction (PTTD) caused by repetitive biomechanical stress and overuse.
Mechanism of Acquired Pes Planus from High-Impact Activities
Repetitive mechanical trauma from weight-bearing activities directly damages the posterior tibial tendon, which is the primary dynamic stabilizer of the medial longitudinal arch. 1 When this tendon fails to function properly due to overuse, the foot's arch progressively collapses, leading to acquired flatfoot deformity. 1
Key Pathophysiologic Factors
Repetitive loading stress: Activities involving sustained weight-bearing with additional load (rucking) or repetitive impact (running, marching) place excessive strain on the posterior tibial tendon and supporting ligamentous structures. 2, 1
Biomechanical cascade: Once the posterior tibial tendon weakens, other foot ligaments and joint capsules progressively fail, unable to compensate for the loss of dynamic arch support. 1
Deformity progression: The foot deformity itself creates a vicious cycle—pes planus increases plantar pressures in the midfoot during walking and standing, perpetuating further tissue damage. 2
Clinical Context and Risk Factors
The development of acquired pes planus from these activities is more likely in individuals with:
Pre-existing flexible pes planus: Up to 25% of adults have deficient medial longitudinal arch in at least one foot, making them more vulnerable to symptomatic progression with high-impact activities. 3
Age-related tendon degeneration: Older individuals are at higher risk as baseline tendon integrity decreases. 1
Additional risk factors: Obesity, hypertension, diabetes mellitus, and inflammatory arthritis increase susceptibility to PTTD. 1
Evidence from Military and Athletic Populations
The repetitive gastric jostling and mechanical trauma from running causes tissue damage, and this same mechanism applies to the foot structures during sustained impact activities. 2 While the cited evidence specifically discusses gastrointestinal effects, the principle of repetitive mechanical trauma causing tissue injury is directly applicable to musculoskeletal structures including the posterior tibial tendon and plantar fascia.
Critical Clinical Pitfall
Do not dismiss foot pain in individuals engaged in marching, rucking, or running as simple overuse—early recognition and offloading are essential to prevent progression to rigid, irreversible deformity. 2 The patient described in diabetes foot management developed midfoot ulceration specifically because pes planus deformity increased plantar pressures during weight-bearing activities, demonstrating how the condition creates pathologic loading patterns. 2
Management Implications
Activity modification is mandatory: Temporary reduction in high-impact weight-bearing activities (marching, rucking, running) allows tissue healing. 4
Orthotic intervention: Custom orthotics with medial longitudinal arch support provide the most significant clinical improvement for symptomatic pes planus. 5
Footwear modifications: Open-backed shoes and appropriate modifications reduce pressure on affected structures. 4
Strengthening exercises: Eccentric strengthening and stretching exercises promote tendon healing and improve foot function. 6, 4
Distinguishing Congenital from Acquired Flatfoot
Flexible pes planus in children typically resolves with age as foot musculature strengthens and is part of normal development. 7, 3 In contrast, acquired adult pes planus from repetitive activities represents pathologic tendon failure requiring intervention. 1 The key distinction is that congenital flexible flatfoot shows normal arch formation during non-weight-bearing or tiptoeing, while acquired PTTD demonstrates progressive loss of this compensatory mechanism. 7