Plantar fasciitis is one of the more frustrating and frequently seen conditions of the foot and makes up approximately 25% of the injuries seen in runners.
The foot is an amazing structure that at one moment is flexible enough to conform to the surface upon which it is walking or running, and the next is a rigid weight bearing structure that allows the body to be propelled efficiently forward. The foot is capable of producing tremendous force, but must also absorb large stresses, making it vulnerable to overuse and injury. Walking can place as much as 2.5 times our body weight through the foot and ankle and running up to 5 times our body weight. Add jumping to the mix and the foot must absorb up to 20 times one’s body weight!
Anatomy and Function
The foot is composed of some 26 bones that make up 34 joints and is controlled by 20 some muscles and tendons. The plantar fascia is broad ligament like structure that runs along the bottom of the foot from the heel bone (calcaneus) to the base of your toes (metatarsal heads) and functions to provide support to the longitudinal arch of your foot and shock absorption. It also converts potential energy into kinetic energy during push off which results in greater foot acceleration.
Pain is usually localized at the bottom of the heel or in the middle of the arch of the foot and is typically worse in the morning and eases after a few minutes of walking. Plantar fascia pain may be felt during the first few minutes of activity and ease or go away once warmed up and again after activity. Walking barefoot on hard surfaces is usually painful (and not recommended) but less severe when wearing supportive shoes with appropriate cushion. As is the case with any injury it is important to note that the more intense and frequent the pain, the more severe the injury tends to be. Always seek the advice of a medical professional for pain lasting more than a few days.
Plantar fasciitis tends to be a chronic, overuse injury in which the accumulation of micro-trauma leads to inflammation and pain. Common causes of plantar fasciitis are training errors, poor footwear and tight and weak musculature of the foot, calf, thigh and hip. Excessive and/or repetitive flattening of the arch of the foot (pronation) increases tension within the plantar fascia and any mechanism or activity that causes excessive pronation has the potential to cause injury.
Training errors are usually related to doing too much too soon and apply to the frequency, duration or intensity (or any combination thereof) of training or activity. Too much stress without adequate rest will fatigue the plantar fascia beyond the ability of the body to repair it and injury will result. Proper footwear designed to meet the specific demands of an activity is important for the purpose of support and shock absorption to reduce excessive pronation. Various muscles of the foot, ankle, thigh and hip influence the mechanics of the foot and if tight and/or weak can cause excessive pronation. Other risk factors include being over weight, high arches (pes cavus), flat feet (pes planus), and leg length discrepancies.
Treatment and Prevention
As with any musculoskeletal or soft tissue injury, treatment starts with activity modification or total rest and ice. If pain continues for more than a few days consult a medical professional. When treating plantar fasciitis, the first thing you want to do is protect the foot as best you can. This includes wearing supportive and cushioned footwear whenever possible and AVOID walking barefoot, wearing sandals and flip-flops as these usually offer little to no support or cushion.
Taping and self-massage with the use of a tennis ball can also be helpful. Icing will help reduce inflammation and pain and the use of a night splint may be indicated. During sleep our feet typically assume a pointed (plantar flexed) posture, which is a shortened position for the plantar fascia. When the alarm goes off and we get out of bed and flex the foot in the other direction (dorsiflexion), we put an immediate stretch on the plantar fascia. Night splints help maintain the dorsiflexed posture so that the plantar fascia isn’t as stressed when you get out of bed.
When able to start training again, analyze your program and identify and fix any training errors that might contribute to your problem. Identify and address any muscle inflexibilities and weaknesses that may contribute to excessive pronation and poor mechanics. This includes the local muscles of the foot and ankle as well as those of the thigh and hip because excessive hip adduction and internal rotation of the thigh contributes to excessive pronation of the foot.
Do not resume training where you left off. Depending on how much time you missed, you may need to start at 25% – 50% of your usual program and increase 10% or so a week from there or as instructed by your physical therapist, doctor or coach. Replace worn shoes and consider a replacement insole in ALL of your shoes for optimal support and cushion.
As with most injuries, the best preventive advice can be summed up in what I call the PETR Principles© which includes proper Preparation, Equipment, Technique and Recovery.
Preparation refers to a conditioning program that incorporates appropriate warm up, flexibility, strength, endurance and balance training. Conditioning not only improves performance but also helps prevent injury by increasing our physiological tolerance and is a must for those that regularly participate in any sport or activity. Flexibility and strength specific to plantar fasciitis include the gastroc-soleus complex, posterior tibialis and peroneal muscles of the calf because these muscles help control the rate and magnitude of pronation. The hip adductors, abductors and external rotators are important because they control internal rotation of the thigh (femur) and shin (tibia) bones, which also influence pronation of the foot.
Equipment includes utilizing the appropriate activity specific equipment such as proper footwear for running or hiking, bike fit for cycling, racquet, and golf club fit, etc. Equipment specific to plantar fasciitis includes footwear that offers sufficient activity specific support and cushioning. Replacement insoles should be considered to supplement support and shock absorption and increase the contact area between the foot and the shoe. In the case of extremely flat feet, arched feet and leg length discrepancies, then a custom orthotic may be needed.
Technique refers to correct form and/or body mechanics when performing a movement or sport. ‘Technique’ as it relates to plantar fasciitis applies more commonly to runners. Proper cadence, posture and leg action are important variables that when applied correctly can reduce the magnitude of pronation, impact stress and improve overall efficiency. Cadence refers to the number of steps taken in a given period of time, commonly one minute and an optimal cadence tends to be a higher cadence.
Recreational runners tend to have a lower cadence of 165 steps per minute compared to 180-192 of more experienced runners. If you find yourself at the lower end of the cadence spectrum, shorten your stride and increase your cadence. To determine your optimal cadence consider a gait analysis by an experienced physical therapist, coach or running shoe sales person. Proper technique is important and can be learned with any movement or sport.
Recovery includes adequate rest within a training program so the body can replenish, adapt and get stronger. Rest and recovery come in different forms, depending on the intensity of an activity or exercise. The more intense the exercise, the more recovery needed. Recovery might include complete rest such as sleep or days off, or ‘relative rest’ such as an easy training day. But without adequate recovery time, rest or sleep, the body becomes more fatigued and more susceptible to injury.
No matter how serious you may or may not be about a particular sport, whether you are a recreational or professional athlete, you may want to consider getting a coach. A little knowledge can go a long way in not only improving performance but in preventing injury.
Although painful and frustrating, plantar fasciitis is treatable and the sooner it is properly diagnosed and treated, the faster it will heal. If you are active or thinking about starting a new training program, be sure to follow the PETR Principles of preparation, equipment, technique and recovery and you can learn to avoid many other overuse type injuries as well.
Partial list of references
Benedict F. Digiovanni, MD; Deborah A. Nawoczenski, PhD, PT; Daniel P. Malay, MSPT; Petra A. Graci, DPT; Taryn T. Williams, MSPT; Gregory E. Wilding, PhD; Judith F. Baumhauer, MD Plantar Fascia-Specific Stretching Exercise Improves Outcomes in Patients with Chronic Plantar Fasciitis: A Prospective Clinical Trial with Two-Year Follow-Up The Journal of Bone and Joint Surgery, vol 88, issue 8 Scientific Articles August 01, 2006
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