Eccentric Training and an Achilles Wrap Reduce Achilles Tendon Capillary Blood Flow and Capillary Venous Filling Pressures and Increase Tendon Oxygen Saturation in Insertional and Midportion Tendinopathy

Abstract

Background

Eccentric training has been demonstrated to decrease pain in patients with Achilles tendinopathy. Whether an Achilles wrap in addition to eccentric training changes parameters of tendon microcirculation in insertional and midportion tendinopathy is not known.

Study Design

Randomized clinical trial; Level of evidence, 2.

Methods

One hundred twelve subjects were recruited. A laser Doppler system assessed capillary blood flow, tissue oxygen saturation, and postcapillary venous filling pressure. Group A performed daily eccentric training for 12 weeks with additional daily Achilles wrap (AirHeel™, 54 tendons of 54 patients), while group B performed the same eccentric training only (64 tendons of 59 patients).

Results

Ninety-one patients (81%) completed the 12-week training period. Tendon oxygen saturation increased significantly in group A at the insertion (70% ± 11% to 75% ± 7%, P = .001) and distal midportion (68% ± 12% to 73% ± 9%, P = .006); this increase was greater than that in group B (69% ± 11% vs 68% ± 15%, P = .041 vs A). Postcapillary venous filling pressures were significantly reduced in group A at 5 of 8 positions at 2 and 8 mm tendon depths (up to 26%, P = .003), while only in 3 of 8 positions in group B (up to 20%, P = .001). Pain on the visual analog scale was 5.1 ± 2.1 vs 3.2 ± 2.7 (A,–37.3%, P = .0001) and 5.5 ± 2.1 vs 3.6 ± 2.4 (B, P = .0001,–34.6%) (P = .486 for A vs B).

Conclusion

Tendon oxygen saturation was increased, and capillary venous clearance facilitated using an Achilles wrap in addition to a daily 12-week eccentric training program. Achilles wrap and eccentric training increased subjective assessment of Achilles tendinopathy, while pain level reduction remained the same in both groups.