Electrical Stimulation of Tendon Healing in Vitro
Nessler and Mass, Clinical Orthopedics and Related Research, April 1987
Summary: 80 tendons from white rabbits were surgically transected and removed from the animals after being surgically repaired. They were divided into 4 groups of 20, and cultured with 10 of each group being electrically stimulated, and half not. A 1.4 volt direct current connected through a 150 kOhm resistor was used for stimulation, at a current of about 7 uA. It was found that currents any higher than this caused discoloration of the tendons. Healing was measured by proline uptake and bridging of the repair site by the epitenon.
Results: "a continuous direct current causes increased tendon cell activity within seven days and the increased activity may persist as long as 42 days." The researchers suggested that externally applied microcurrents may be preferable in future studies.
Electrical Energy and Soft-Tissue Injury Healing Sportcare and Fitness
Stanish and Gunlaughson, Sept/Oct 1988
Summary: This article is a summary of research into tendon healing acceleration, including human injuries of the anterior cruciate ligament and the Achilles tendons: "While the results are subjective, the individuals in both groups appear to have returned to usual activities more quickly, and have greater mobility, than people treated more conventionally".
Low-intensity Pulsed Galvanic Current and the Healing of Tenotomized Rat Achilles Tendons: Preliminary Report Using Load-to-Breaking measurements
Oweye, Spielholz and Nelson, Archives Physical Med Rehab, Vol. 68, July 1987
Summary: 60 rats were divided into three groups of 20. One was unstimulated, one group had their Achilles tendons stimulated with positive (anodal) current, and the third group's tendons were stimulated with negative (cathodal) currents. A current of 75 microamps, at 10 Hz was used. Results: "The group treated with anodal current withstood significantly greater loads (p<0.001) than did either the group which healed normally (i.e. without stimulation) or the group treated with cathodal currents".