Effects of Laser Acupuncture on Longitudinal Bone Growth in Adolescent Rats

“This study investigated the effects of laser acupuncture on growth, particularly longitudinal bone growth in adolescent male rats[2 weeks old]. Laser acupuncture was performed once every other day for a total of 9 treatments over 18 days to adolescent male rats.  The bone growth rate and the heights of growth plates were significantly increased by laser acupuncture. BMP-2 but not IGF-1 immunostaining in growth plate was increased as well. LA promotes longitudinal bone growth in adolescent rats, suggesting laser acupuncture may be a promising intervention for improving the growth potential for children and adolescents.”

“Laser acupuncture is [a type] of low-level laser therapy (LLLT), a noninvasive form of phototherapy, which is defined as the stimulation of traditional acupoints with low-intensity, nonthermal laser irradiation”

“Laser acupuncture was performed by laser stimulation using Lapex-2000 (Meridian Medical Inc. Vancouver, Canada), a semiconductor-based low level laser therapy (LLLT) device emitting a cold red laser (635–680 nm/40 mW). Before laser acupuncture was applied, both hind limbs were shaved with an electric clipper, paying attention to not hurt the skin. Acupoints ST36 (Zusanli) and SP6 (Sanyinjiao) commonly used in the treatment of growth stimulation were selected in this study”<-The LAPEX-2000 is typically used for liposuction.  I looked for a few prices and it runs about 30,000$.

Both Acupoint ST36 and SP6 are nowhere near the synovial joint stimulated by LSJL.  It’s possible that Laser acupuncture would produce better results if they stimulated ST35 and SP5.

“Each acupoint of rats lightly restrained by hands without anesthesia was stimulated, bilaterally, for 30 seconds (energy density of 1.2 W/cm2) by holding a laser probe with a spot size of the laser of 3 mm in diameter in contact with, and perpendicular to, the acupoints; each treatment session lasted 120 seconds.”

“Neither Body weight nor the nose to tail length was different between control and LA-treated groups”

“The longitudinal bone growth rate in normal adolescent rats was 195.9 ± 17.5 μm/day and laser acupuncture was shown to promote bone growth, increasing the rate to 315.1 ± 48.8 μm/day”<-that’s very significant.  Although growth rate does not always equal final height.

Here’s a laser stimulated growth plate.  The height of the hypertrophic zone and the total growth plate height increased but not the height of the proliferative zone.  Hypertrophic zone was increased versus controls from approx 300 to 350 or 17% whereas total growth plate increased from about 500 to 600 or 20%.  So most of the growth plate height increase was due to the hypertrophic zone.

laser acupuncture growth plate is bigger.

This is in contrast to LSJL where the proliferative zone increased in length as well as the total height of the growth plate which indicates that LSJL is much more promising for ectopic growth plate formation than laser acupuncture.

“The height of proximal tibia growth plate in normal adolescent rats was 511.3 ± 9.2 μm. Following laser acupuncture treatment, growth plate height increased to 587.5 ± 13.0 μm”

“LLLT[Low level laser therapy] increases cell growth, cell regeneration, and cellular activity”

The main takeaway from this study is that LSJL is special in it’s stimulation of both the proliferation of chondrocytes and of layers the growth plate note involving the proliferative or hypertrophic zone which would be the layers from which new growth plates are formed.