Effectiveness of Specifically Optimized Off-the-counter Foot Orthosis for the Management of Mechanical Foot Pains in the Subtle Cavus Foot Type: A Pilot-controlled Study

As off-the-counter foot orthoses are readily available and have an economic advantage, they are increasingly being used by healthcare professionals to treat mechanical foot pains in place of custom foot orthosis. However, there is a lack of available evidence to determine if a plain off-the-counter foot orthosis that aims to contours to the foot or a specifically optimized off-the-counter foot orthosis utilizing the type of orthotic design proposed by Abbasian and Pomeroy is more effective in the management of mechanical foot pains in the Subtle Cavus foot type.

This study proposal seeks to fill the gap in this area.

Primary Aim:

To investigate the effectiveness of specifically optimized off-the-counter foot orthosis designed for the Subtle Cavus foot type in improving patient reported outcomes in patients with mechanical foot pains when compared to plain off-the-counter foot orthosis.

Primary Null Hypothesis:

There is no difference in pain and functional scores reported by patients between specifically optimized off-the-counter foot orthosis and plain off-the-counter foot orthosis in patients with mechanical foot pains at four, eight and twelve weeks of intervention.

In our study, the Subtle Cavus foot refers to the flexible idiopathic forefoot-driven Pes Cavus that can be clinically recognised with a positive "Peek a Boo" sign, inverted hindfoot position in weight bearing stance and Positive Coleman Block Test as reported by Manoli and Graham in 2005.

Also, for our study, mechanical foot pains are limited to clinically diagnosed Plantar Fasciitis, Achilles Tendinopathy, Peroneal Strain or Metatarsalgia:

Plantar Fasciitis is clinically diagnosed using the following history and physical examination findings:

• Plantar medial heel pain /or pain along the plantar fascia: most noticeable with initial steps after a period of inactivity but also worse following prolonged weight bearing
• Heel pain /or pain along the plantar fascia precipitated by a recent increase in weightbearing activity
• Pain with palpation of the proximal insertion of the plantar fascia /or along the band of plantar fascia structure

Achilles Tendinopathy is clinically diagnosed using the following history and physical examination findings:

Midportion Achilles Tendinopathy:

• Self-reported localized pain and perceived stiffness in the Achilles tendon following a period of inactivity (eg, sleep, prolonged sitting) lessen with an acute bout of activity and may increase after the activity.
• Symptoms are frequently accompanied by Achilles tendon tenderness.
• Pain located 2 to 6 cm proximal to the Achilles tendon insertion that began gradually and pain with palpation of the midportion of the tendon to diagnose midportion Achilles tendinopathy

Insertional Achilles Tendinopathy:

• Self-reported pain that is aggravated by activity and stiffness that is associated with prolonged periods of rest.
• Pain and tenderness with palpation within the distal 2 cm of the Achilles tendon.
• Redness and swelling over area of Achilles Tendon insertion over posterior heel

Peroneal Strain is clinically diagnosed using the following history and physical examination findings:

• Pain and swelling posterior to the lateral malleolus
• Pain with active eversion and dorsiflexion against resistance
• May have a history of chronic lateral ankle pain and instability
• Pain and tenderness with palpation along the course of the peroneal tendons

Metatarsalgia is clinically diagnosed using the following history and physical examination findings:

• Self-reported pain during the propulsive phase of gait. The pain is localized underneath the prominent metatarsal heads
• The plantar soft tissue can be swollen and inflamed.
• Presence of hyperkeratosis over tender areas may be present
• Pain and tenderness with palpation of plantar metatarsophalangeal joints

Secondary Aim:

To investigate the effectiveness of specifically optimized off-the-counter foot orthosis designed for the Subtle Cavus foot type in improving patient reported outcomes in patients with mechanical foot pains pre- and post-intervention.

Secondary Null Hypothesis:

There is no difference in pain and functional scores reported by patients after introduction of specifically optimized off-the counter foot orthosis pre- and post-intervention at initial to four, initial to eight and initial to twelve weeks of intervention.