- Local anaesthetic injection of the Achilles appears to immediately increase calf function and reduce pain and catastrophizing in subjects with Achilles tendinopathy, suggesting peripheral nociceptive input may be a key factor.
BACKGROUND & OBJECTIVE
People with Achilles tendinopathy (AT) demonstrate motor dysfunction, especially of the calf complex. This motor dysfunction may be linked to psychological factors such as fear of movement. For example, research has found subjects with kinesiophobia regained less calf muscle endurance (measured by heel raises) following a tendon loading programme (1). The presence of pain appears to reduce muscle activation (2), suggesting peripheral nociceptive input may cause motor dysfunction. There is conflicting evidence regarding whether nociplastic pain (driven by sensitization of the central nervous system) is a factor in persistent Achilles tendinopathy.
This study sought to identify indicators of altered central processing (which may suggest nociplastic pain) and determine which of these indicators remain after a local anaesthetic injection into the Achilles tendon in patients with Achilles tendinopathy.
Peripheral, nociceptive input can be an important piece of the pain puzzle in Achilles tendinopathy.
The study design was a mechanistic, non-randomized controlled trial. 23 patients with Achilles tendinopathy were recruited alongside 23 controls matched for age, sex, and BMI. Laboratory-based testing of movement-evoked pain ratings, motor performance, pain psychology questionnaires and sensor testing was