The Relationship Between Physical Activity and Pain, Pain-Related Cognitions, and Central Sensitization in Patients With Midportion Achilles Tendinopathy

Background: Achilles tendinopathy is one of the most prevalent lower limb tendinopathies that, while commonly present in physically active people, can affect men and women of all ages and lifestyles. Although this condition can significantly affect patients' daily lives, not much is known regarding that which contributes to negative influences on patients' physical activity. Purpose: To explore the association between objectively measured physical activity behavior and pain, kinesiophobia, pain catastrophizing, and symptoms of central sensitization in patients with midportion Achilles tendinopathy. Study Design: Cohort study; Level of evidence, 2. Methods: For 130 adult patients with midportion Achilles tendinopathy (mean age, 47; 55% female), physical activity was measured via wrist-worn actigraphy and assessed as daily step count and active minutes. The latter includes lightly, fairly, and very active minutes, as well as total active minutes. Linear regression analyses explored the relationship between physical activity behavior and pain intensity, pain interference, kinesiophobia, pain catastrophizing, and central sensitization. All analyses were controlled for age and sex. Results: A significant association was found between pain intensity and participants' daily step count scores (regression coefficient, -591; 95% CI, -994 to -187) and very active minutes (regression coefficient, -3.76; 95% CI, -5.86 to -1.67). Pain intensity was not significantly associated with patients' total, lightly, or fairly active minutes. Similarly, no significant associations were found between physical activity and pain interference, kinesiophobia, pain catastrophizing, and symptoms of central sensitization. Conclusion: Only pain intensity of patients with midportion Achilles tendinopathy is significantly associated with their daily steps and time spent being very physically active, as determined via actigraphy.