A higher number of active trigger points (TrPs) was found to be associated with increased pain and related disability in patients with plantar heel pain, according to a study published in Pain Medicine.
The study included participants with unilateral chronic plantar heel pain (n=35) and matched comparable healthy controls (n=35). An assessor who was blinded to the participants’ conditions assessed TrPs in the flexor hallucis brevis, adductor hallucis, quadratus plantae, and internal gastrocnemius. The researchers used a 1 to 10 numeric pain rating scale, the Foot Function Index, and the Foot Health Status Questionnaire to assess pain and related disability, respectively.
In participants with plantar heel pain, the number of TrPs was 4±3 (2.5±2 active TrPs, 1.5±1.8 latent TrPs). Healthy controls had only latent TrPs, with a mean of 1±1. Participants with plantar heel pain had more latent TrPs compared with healthy controls (P =.03). TrPs in participants with plantar heel pain were most commonly located in the quadratus plantae (n=20; 62.5%) and flexor hallucis brevis (n=19; 59%). A higher number of active TrPs — but not latent — was associated with higher foot pain (P <.01), higher impact of foot pain (P <.05), and worse related disability (P <.05).
“The current results provide further evidence in favor of the concept that active TrPs may be associated with plantar heel pain symptoms,” the researchers noted.
Ortega-Santiago R, Rios-Leon M, Martin-Casas P, et al. Active muscle trigger points are associated with pain and related disability in patients with plantar heel pain: a case-control study [published online April 15, 2019]. Pain Med. doi:10.1093/pm/pnz086