Background: Plantar heel pain is a common condition but little is known about the relationship between muscle strength and plantar heel pain.
Objectives: To review the evidence relating to muscle strength in those with and without plantar heel pain.
Methods: We systematically reviewed the literature by searching key databases. Included studies assessed muscle strength (or endurance or size as proxies) in those with and without plantar heel pain. A modified quality index was used to assess risk of bias. Meta-analysis was performed where possible.
Results: Seven studies met the eligibility criteria. The quality of studies was generally high (score range 11 to 16 out of 17). Hallux plantarflexion, lesser toe plantarflexion, ankle dorsiflexion, ankle inversion and ankle eversion strength were reduced in those with heel pain compared to those without, however there was inconsistency in the findings between studies. Calf muscle endurance found no difference between those with and without plantar heel pain. Generally, foot muscle volume was smaller for people with plantar heel pain compared to those without.
Conclusion: People with plantar heel pain have reduced strength and volume of the foot muscles, but there is no discernible change in calf muscle endurance. It is unclear whether muscle weakness is a cause or consequence of plantar heel pain. However, these findings suggest that the role of muscle strengthening in the treatment of plantar heel pain is worthy of further investigation.