Foot pain is common in the general population. Plantar fasciopathy may affect 7% of the population at some time in their lives, but the incidence increases with age. This plantar problem is characterized by severe pain under the foot (at plantar level), which can be very incapacitating and disabling. This can lead to absenteeism from work, particularly for employees working in a standing posture. Various therapeutic avenues can be used to reduce pain and improve functionality, such as physiotherapy, infiltrations and surgery. In this research project, the propose the use of a conservative approach through the use of foot orthoses, which appears to be effective in reducing pain. The aim of the study is thus to better understand the effect of foot orthoses on postural balance and walking in workers with plantar fasciopathy. Participants will be assessed at baseline and eight weeks later to observe measured changes and clinical improvements following orthotic wear. Balance and gait pattern will be assessed using technological tools that have been validated in this respect. Participants will also be asked about their pain intensity. The hypothesis is that wearing the orthosis will improve the participants' balance and walking abilities, as well as reduce the level or intensity of their pain. In addition, this study could have an impact on the rate of absenteeism from work from current context of labour shortages.

Plantar fasciopathy is a musculoskeletal disorder, known as a degeneration of the plantar fascia associated with a sensation of pain at plantar level. This disorder, for which around 2 million people a year receive treatment, has a prevalence of 3.6% to 7%, affecting both men and women between the ages of 45 and 64, and increasing with age. People aged between 25 and 65, who make up the majority of the working population, present 83% of plantar fasciopathy cases. According to CNESST statistics for 2022, 15,310 files opened concerned musculoskeletal disorders of the lower limb, 2133 of which involved the feet. There is also evidence of a possible cause-effect relationship between the number of hours spent standing or walking and the risk of developing plantar fasciopathy, which is indeed a major risk factor for many active workers. People with plantar fasciopathy will be absent from work more regularly, contributing to lower productivity at work. In addition to reduced work productivity, the cost of treatment has been estimated at US$584 million in the United States alone. In addition to pain, other deficits can be observed in people with plantar fasciopathy. A recent study also demonstrated its impact from a biomechanical point of view, notably on postural balance and gait in young adults suffering from this health problem. A number of treatments are currently used to treat this clinical foot condition, both conservatively and surgically. Among the most widely used conservative treatments, foot orthoses have been shown to be effective in reducing pain, despite the paucity of studies on the issue. Some studies have also demonstrated its effects on balance measures. Or, balance afferents originate from the somatosensory system, and tendon vibration can disrupt this system. However, few studies have measured its effects on postural control reactions via tendon vibration following orthotic use and in an ageing population, and no study has specifically investigated the effect of plantar orthoses in cases of plantar fasciopathy on gait pattern parameters in ageing workers.

Inclusion Criteria:

• Present a history of pain under the heels for more than 3 months
• Have a diagnosis of plantar fasciopathy
• Pain of at least 3/10 under the heel
• Have post-static dyskinesia
• To be in the job market (adults between 20 and 65 years)

Exclusion Criteria:

• Severe systemic diseases
• Red flags (e.g. tumors),
• Musculoskeletal deformities affecting the lower limbs
• Musculoskeletal surgery