Eccentric training decreases paratendon capillary blood flow and preserves paratendon oxygen saturation in chronic Achilles tendinopathy

▸ Knobloch K, Kraemer R, Jagodzinski M, Zeichen J, Meller R, Vogt PM. J Orthop Sports Phys Ther 2007;37:269–76

Background:

In patients suffering from Achilles tendinopathy there are changes in tendon and paratendon microcirculation (at the insertion and the mid-portion) – eccentric training is a common treatment for this condition.

Research question/s:

Does 12 weeks of daily eccentric training alter paratendon microcirculation in individuals suffering from chronic Achilles tendinopathy?

Methodology:

Subjects: 20 patients with chronic Achilles tendinopathy.

Experimental procedure: Based on the location of the tendinopathy (insertion (I) or mid-portion (MP)) subjects were randomly allocated to either a control group (CON = 5, I = 3, MP = 2) or an eccentric training group (ECC = 15, I = 9, MP = 6) (3 sets of 15 reps daily) for 12 weeks. Pain (VAS) as well as capillary blood flow (flow), tissue oxygen saturation (SO₂), and post capillary venous filling pressure (rHb) were measured (using a laser Doppler system at 8 paratendon locations at depths of 2 (superficial) and 8 mm (deep) before and after 12 weeks.

Measures of outcome: Pain, blood flow, tissue oxygen saturation, post-capillary venous filling pressure.

Main finding/s:

Pain: There was a 48% reduction in pain in the ECC group after 12 weeks (Pre 4.1 (SD 2.9), Post 2.1 (2.2), p<0.05).

Blood flow: There was a decrease in deep paratendon blood flow at the mid-portion paratendon location (p<0.05) while superficial blood flow at …