Can parachuting cause pes planus (flat foot) and hallux valgus (bunions)?

Can Parachuting Cause Pes Planus and Hallux Valgus?

Yes, parachuting can cause or exacerbate pes planus (flat feet) and hallux valgus (bunions) due to repetitive high-impact landings that place excessive stress on foot structures.

Mechanism of Injury in Parachuting

Parachuting involves significant landing forces that primarily affect the lower extremities, with the ankle and foot being the most commonly injured areas:

• Landing is the most dangerous phase of parachuting, with 80% of injuries involving the lower extremity 1
• The ankle is the most commonly affected site (47% of lower extremity injuries) 2
• The foot accounts for 33.5% of all parachute-related injuries 3

Biomechanical Impact on Foot Structure

The repetitive high-impact landings in parachuting create biomechanical stress that can lead to:

1. Pes Planus (Flat Foot):

   • Repeated landing impacts can weaken the supporting structures of the foot arch
   • Excessive pronation during landing can gradually stretch the posterior tibial tendon and plantar ligaments
   • Guidelines recognize that pes planus can result from repetitive biomechanical stress 4

2. Hallux Valgus (Bunions):

   • Improper landing technique can create abnormal forces across the first metatarsophalangeal joint
   • Research shows that pes planus is associated with hallux valgus development 5
   • The combination of foot deformities often occurs together, with flat feet predisposing to bunion formation

Risk Factors and Associations

Several factors increase the risk of developing these foot conditions through parachuting:

• Age: Injury risk in parachuting increases with age 1, 3
• Experience level: Novice jumpers have significantly higher injury rates (19.7 vs 4.5 injuries per 1000 jumps) 1
• Landing technique: About 70% of parachuting injuries are caused by improper landing fall technique 1
• Pre-existing foot structure: Those with pre-existing mild pes planus may experience progression to more severe deformity 5

Clinical Implications

The relationship between these conditions is significant:

• Pes planus can lead to more severe hallux valgus deformity 5
• Patients with pes planus who develop hallux valgus often present with more severe deformity requiring surgical intervention 5
• Achilles tendinopathy, which can occur with parachuting injuries, is often associated with excessive foot pronation and pes planus 4

Management Considerations

For military personnel or recreational parachutists with these conditions:

1. Preventive Measures:

   • Custom-made insoles to redistribute plantar pressure and provide arch support 4
   • Proper footwear with adequate support and cushioning 4
   • Training in proper landing techniques to minimize impact forces

2. Treatment Options:

   • For symptomatic pes planus: shoe orthotics to correct overpronation 4
   • For hallux valgus: custom-made footwear to accommodate deformity and relieve pressure 4
   • Physical therapy focusing on foot and ankle strengthening exercises 4

Important Caveats

• Not all flat feet are pathological - pediatric flatfoot often resolves by adolescence and may be physiologic 6
• Asymptomatic pes planus generally doesn't require intervention 6
• The presence of pain, progressive deformity, or functional limitation should prompt medical evaluation
• Individuals with pre-existing foot deformities should be cautious about participating in high-impact activities like parachuting

Conclusion

Parachuting can both cause and worsen pes planus and hallux valgus through repetitive high-impact landings. These conditions are biomechanically linked, with flat feet often predisposing to bunion formation. Proper landing technique, appropriate footwear, and custom orthotics can help mitigate these risks for those who participate in parachuting activities.