Patellofemoral pain syndrome (PFPS) is a common problem among military soldiers in training. In fact, it’s the main reason soldiers are given a medical discharge. PFPS is also common among runners. PFPS causes pain behind the kneecap during running, squatting, and stair climbing.
Even though PFPS is common, we still don’t know exactly what causes it. Researchers suggest factors such as muscle weakness, loss of muscle control, and changes in the foot and ankle. How do we treat something when we don’t know what causes it? What works for one person may not work for everyone.
In this study, physical therapists in the military looked at the use of a shoe insert for PFPS. The insert is called a foot orthotic. They used an off-the-shelf and ready-to-use orthotic. It’s a premolded full-length insole that fits inside the shoe. It has a firm arch support and heel cushion. The shoe insert was combined with a modified training program.
Forty-five men and women with PFPS were examined before wearing the inserts. Range of motion was measured to assess muscle length. Many other measures of the knee and lower leg were taken, including alignment of the bones in the foot and ankle. The inserts were worn at all times for three weeks. All soldiers were given instructions to avoid kneeling, squatting, and deep knee bends. Marching was limited to one mile, with no running during the first seven days.
Sixty percent of the soldiers had a successful response with the orthotics. Success was defined as a 50 percent decrease in pain. The researchers found three factors linked with successful use of ready-to-use orthotics. Patients with an inflexible foot got the most help from the orthotics. They all had a flat foot, limited big toe extension, and only a small amount of movement of the navicular bone in the foot.
Orthotics can cost quite a bit when custom-made for each patient. Off-the-shelf orthotics are readily available and cost less. Finding out which patients can get relief from PFPS with the off-the-shelf type is helpful and can save money. The authors suggest that anyone who has PFPS and one or more of these risk factors may respond well to an off-the-shelf foot orthotic. They think the orthotics absorb the shock and put less strain on the knee.