Introduction Tendon microcirculation is considered to be an important factor in tendinosis and the tendon healing process [Fenwick, 2002]. The present study investigated microcirculatory changes in the Achilles tendon in healthy subjects resulting from interventions with three kinds of physical agents including thermal, optical, and mechanical stimulations.

Methods Thirty-seven healthy adults between 20 and 40 years of age were recruited and randomly assigned into four groups. Participants in each group received an intervention consisting of one of four kinds of physical agents: ultrasound (USD), low level laser (LLL), or vibration gun (VG). A randomised block design was used to reduce any influences due to gender. Red laser lights were used to measure Achilles tendon microcirculation (total haemoglobin [THb] and oxygen saturation [StO2]) before and after the interventions. In each group, interventions consisting of two different doses or involving different target tissues were applied on the right and left leg (in random order). In the USD group, 0.8 or 1.2 W/cm² of intensity was applied on bilateral Achilles tendons. In the LLL group, 18 or 5.4 J of total intensity was applied on bilateral Achilles tendons. In the VG group, the interventions were randomly targeted on the Achilles tendons or calf muscles of either leg. There were 20-minute intervals between to reduce reciprocal influences. Wilcoxon sign rank tests were used to assess the pre- and post-intervention microcirculatory data in each group, and the alpha level was set at 0.05.

Results There were 12 subjects (6 males) in the USD group, 11 (6 males) in the LLL group, and 14 (7 males) in the VG group. The results are showing in Figure 1. The THb and StO₂ values significantly increased after the ultrasound intervention for intensities of both 0.8 and 1.2 W/cm². Both values were also significantly increased in response to the vibration gun intervention targeted on the Achilles tendon. No significant THb and StO₂ differences were found following the interventions in the other groups.

Discussion The study results demonstrate the microcirculatory effects of ultrasound and vibration gun interventions on the Achilles tendon. The results support the efficacy of the two physical agents on tendon healing from the viewpoint of tendon microcirculation.

• Download figure
• Open in new tab
• Download powerpoint

Abstract 107 Figure 1

Figures show the pre- and post-intervention comparisons of THb and StO₂ values in the three intervention groups. Blue columns indicate the mean values of pre-intervention data. Green columns represent the mean values of post-intervention data. Error bars: ± 1 SD. *: p ≤ 0.05

Reference Fenwick et al. Arthritis Res. 2002;4(4):252–260