Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Mar-Apr;47(2):178-83.
doi: 10.4085/1062-6050-47.2.178.

Limb blood flow after class 4 laser therapy

Kelly A Larkin  1 , Jeffrey S Martin, Elizabeth H Zeanah, Jerry M True, Randy W Braith, Paul A Borsa
Affiliations

Limb blood flow after class 4 laser therapy

Kelly A Larkin et al. J Athl Train. 2012 Mar-Apr.

Abstract

Context: Laser therapy is purported to improve blood flow in soft tissues. Modulating circulation would promote healing by controlling postinjury ischemia, hypoxia, edema, and secondary tissue damage. However, no studies have quantified these responses to laser therapy.

Objective: To determine a therapeutic dose range for laser therapy for increasing blood flow to the forearm.

Design: Crossover study.

Setting: Controlled laboratory setting.

Patients or other participants: Ten healthy, college-aged men (age = 20.80 ± 2.16 years, height = 177.93 ± 3.38 cm, weight = 73.64 ± 9.10 kg) with no current history of injury to the upper extremity or cardiovascular conditions.

Intervention(s): A class 4 laser device was used to treat the biceps brachii muscle. Each grid point was treated for 3 to 4 seconds, for a total of 4 minutes. Each participant received 4 doses of laser therapy: sham, 1 W, 3 W, and 6 W.

Main outcome measure(s): The dependent variables were changes in blood flow, measured using venous occlusion plethysmography. We used a repeated-measures analysis of variance to analyze changes in blood flow for each dose at 2, 3, and 4 minutes and at 1, 2, 3, 4, and 5 minutes after treatment. The Huynh-Feldt test was conducted to examine differences over time.

Results: Compared with baseline, blood flow increased over time with the 3-W treatment (F(3,9) = 3.468, P < .011) at minute 4 of treatment (2.417 ± 0.342 versus 2.794 ± 0.351 mL/min per 100 mL tissue, P = .032), and at 1 minute (2.767 ± 0.358 mL/min per 100 mL tissue, P < .01) and 2 minutes (2.657 ± 0.369 mL/min per 100 mL tissue, P = .022) after treatment. The sham, 1-W, and 6-W treatment doses did not change blood flow from baseline at any time point.

Conclusions: Laser therapy at the 3-W (360-J) dose level was an effective treatment modality to increase blood flow in the soft tissues.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Experimental protocol.
Figure 2.
Figure 2.
3-W dose response over time. Abbreviations: BL, baseline; T-2, mean during minute 2 of treatment; T-3, mean during minute 3 of treatment; T-4, mean during minute 4 of treatment; PT-1, mean at posttreatment minute 1; PT-2, mean at posttreatment minute 2; PT-3, mean at posttreatment minute 3; PT-4, mean at posttreatment minute 4; PT-5, mean at posttreatment minute 5. a Significant increase in blood flow from baseline.
Figure 3.
Figure 3.
1-W versus sham dose response over time. Abbreviations: BL, baseline; T-2, mean during minute 2 of treatment; T-3, mean during minute 3 of treatment; T-4, mean during minute 4 of treatment; PT-1, mean at posttreatment minute 1; PT-2, mean at posttreatment minute 2; PT-3, mean at posttreatment minute 3; PT-4, mean at posttreatment minute 4; PT-5, mean at posttreatment minute 5.
Figure 4.
Figure 4.
6-W dose response over time. Abbreviations: BL, baseline; T-2, mean during minute 2 of treatment; T-3, mean during minute 3 of treatment; T-4, mean during minute 4 of treatment; PT-1, mean at posttreatment minute 1; PT-2, mean at posttreatment minute 2; PT-3, mean at posttreatment minute 3; PT-4, mean at post-treatment minute 4; PT-5, mean at posttreatment minute 5.
See this image and copyright information in PMC

References

    1. Bjordal JM, Johnson MI, Iversen V, Aimbire F, Lopes-Martin RA. Photo-radiation in acute pain: a systematic review of possible mechanisms of action and clinical effects in randomized placebo-controlled trials. Photomed Laser Surg. 2006;24(2):158–168. - PubMed
    1. Laakso EL, Cabot PJ. Nociceptive scores and endorphin-containing cells reduced by low-level laser therapy (LLLT) in inflamed paws of Wistar rat. Photomed Laser Surg. 2005;23(1):32–35. - PubMed
    1. Bjordal JM, Couppe C, Chow RT, Tuner J, Ljunggren EA. A systematic review of low level laser therapy with location-specific doses for pain from chronic joint disorders. Aust J Physiother. 2003;49(2):107–116. - PubMed
    1. Enwemeka CS, Parker JC, Dowdy DS, Harkness EE, Sanford LE, Wood-ruff LD. The efficacy of low-power lasers in tissue repair and pain control: a meta-analysis study. Photomed Laser Surg. 2004;22(4):323–329. - PubMed
    1. Wertz RL. A higher power: therapeutic laser units feature drastically stronger intensity levels. Adv Phys Ther Rehabil Med. 2006;18(5):52.