The Effectiveness of the Polarized Low-Level Laser in the Treatment of Patients With Myofascial Trigger Points in the Trapezius Muscles

Effectiveness of polarized polychromatic light therapy on myofascial trigger points in chronic non-specific low back pain: a single blinded randomized controlled trial

Background

Phototherapy has been used for the treatment of chronic low back pain. However, the effect of linear polarized polychromatic light (PL) has not been examined on myofascial trigger points in patients with chronic non-specific low back pain (NSLBP).

Objectives

To investigate the effectiveness of PL on pain intensity, pain sensitivity of active myofascial trigger points (MTrPs) in gluteus medius (GM) and quadratus lamborum (QL) muscles, back disability, and lumbar range of motion in chronic NSLBP.

Methods

Forty-two participants of both genders with chronic NSLBP were randomly allocated into two equal groups: group A (Linear polarized polychromatic light (PL): 21 participants received polarized light therapy in the range of red and near-infrared rays on myofascial trigger points of bilateral GM and QL muscles for 5 min/point followed by stretching and strengthening exercises for 4 weeks. Group B (Sham PL): 21 participants received the same program but with sham linear polarized polychromatic light therapy. Numeric pain rating scale, pressure algometer, and Roland-Morris Disability Questionnaire were used to measure pain intensity, pain sensitivity (as represented by pain pressure threshold (PPT) of MTrPs of the target muscles and back disability respectively. Further, lumbar flexion, extension, and bilateral rotation were examined with a tape measure, while bilateral side bending were examined with a universal goniometer.

Results

After the intervention program, significant improvements (p < 0.05) in pain intensity, PPT of MTrPs of left GM (Effect Size (ES): 1.23) and bilateral QL muscles (ES Rt QL: 0.9; Lt QL: 1.56) were found in group A in comparison with group B. Nevertheless, the two groups displayed similar improvements (p > 0.05) in lumbar range of motion and back disability.

Conclusion

Linear polarized polychromatic light therapy in the range of red and near-infrared rays improves pain intensity and pain sensitivity of myofascial trigger points in chronic NSLBP.

Trial registration

PACTR, PACTR202111577053926. Registered 22 June 2019-Prospectively registered.

Immediate Evaluation of the Effect of Infrared LED Photobiomodulation on Childhood Sleep Bruxism: A Randomized Clinical Trial

The gold standard for the management of sleep bruxism (SB) is the use of a rigid occlusal splint; however, there are limitations for its use in children and alternatives to the management of SB are needed. Photobiomodulation therapy has been used with positive results in temporomandibular disorders. This study aimed to evaluate the effects of photobiomodulation therapy with infrared LED in children with SB. Thirty children were divided into three groups: Group 1: control/absence of bruxism (n = 10); Group 2: SB treated with infrared LED (n = 10); Group 3: SB treated with occlusal splint (n = 10). Electromyographic evaluation of masseter, anterior temporalis, and upper trapezius, and salivary dopamine levels were assessed before and after treatments. Data were statistically analyzed using two-way mixed model ANOVA. An increase in the temporalis and right masseter EMG activity at rest was observed in Group 3, with large effect size (p < 0.05). Left masseter and temporalis EMG activity did not differ over time in the LED group, similar to the control group. Moreover, the EMG activity of masticatory muscles during chewing and upper trapezius muscle did not differ over time in all groups. The results also pointed to a difference in the levels of dopamine between children with and without SB, with Group 3 showing higher levels in the pre-treatment time compared to controls (p < 0.025). In conclusion, an increase in the masticatory muscles activity at rest was observed in children undergoing splint therapy. Moreover, a difference in the levels of salivary dopamine was found between children with and without SB.

Acute Effects of Tecar Therapy on Skin Temperature, Ankle Mobility and Hyperalgesia in Myofascial Pain Syndrome in Professional Basketball Players: A Pilot Study

(1) Background: Myofascial pain syndrome (MPS) is a clinical condition characterized by localized non-inflammatory musculoskeletal pain caused by myofascial trigger points. Diathermy or Tecar therapy (TT) is a form of noninvasive electro-thermal therapy classified as deep thermotherapy based on the application of electric currents. This technique is characterized by immediate effects, and its being used by high performance athletes. (2) Methods: A total of thirty-two participants were included in the study who were professional basketball players. There was a 15-person Control Group and a 17-person Intervention Group. TT was applied in the Intervention Group, while TT with the device switched off (SHAM) was applied in the Control Group. The effects were evaluated through the Lunge test, infrared thermography, and pressure threshold algometry at baseline, 15, and 30 min after the intervention. (3) Results: the Intervention Group exhibited a greater increase in absolute temperature (F_[1,62] = 4.60, p = 0.040, η²_p = 0.13) compared to the Control Group. There were no differences between the groups in the Lunge Test (F_[1.68,53.64] = 2.91, p = 0.072, η²_p = 0.08) or in pressure algometry (visual analog scale, VAS) (F_[3.90] = 0.73, p = 0.539, η²_p = 0.02). No significant short-term significant differences were found in the rest of the variables. (4) Conclusions: Diathermy can induce changes in the absolute temperature of the medial gastrocnemius muscle.