Photobiomodulation Therapy Using Infrared (808 nm) Low Level Laser Therapy Associated with Strength Training in Knee Osteoarthritis: A Randomized placebo-controlled clinical trial

Abstract

Mechanisms for significant clinical and statistical benefits of photobiomodulation (PBMT) in the treatment of knee osteoarthritis (KOA) include anti-inflammatory effects, optimization of tissue repair, improved muscle function and analgesia. The effectiveness of (PBMT) associated with strength training (ST), in the form of strength training, has been investigated in randomized clinical trials, but the results are not well clarified. The aim of this study was to evaluate the effects of ST associated with PBMT on joint pain intensity, range of motion, physical function and muscle strength of the quadriceps femoris and hamstrings in patients diagnosed with KOA. Twenty-eight adult patients of both genders with KOA were randomly distributed in 2 treatment groups, performed 3 times a week, for 6 weeks: ST Group (ST), submitted to stretching, self- mobilization, muscle strengthening and sensorimotor training and ST and STP Group (STP), submitted to the same program as the ST followed by infrared laser irradiation (Therapy XT, DMC, São Carlos, Brasil, l= 808 nm, P= 100mW, 5 points in the medial joint region and 4 points lateral, 3 J/point, 30 s/point). Blinded evaluators assessed pain at movent and no movement and range of motion using Analogic Visual Scale and goniometry, respectively. To assess physical function, the WOMAC questionnaire (Western Ontario and MacMaster University Osteoarthritis Index) and functional tests were used: Sit and stand test; 2 min-walk test. The muscular strength of the quadriceps and hamstrings were measured using an isometric dynamometer. The evaluations were performed in 4 moments: before (EV0), during (EV1: 3 weeks of treatment), at the end (EV2: after 6 weeks of treatment) and 30 days after the end of treatment (follow-up). The STP group showed a significant reduction in pain intensity at rest and at movement in EV1, as well as, significant improvement in relation to stiffness, total WOMAC and knee flexion amplitude, an improvement in physical function and an increase in muscle strength of quadriceps femoris when compared to ST group (p <0.05). In the assessment of the strength of the hamstring muscles, there was no significant difference between the groups at any time evaluated (p> 0.05). ST associated with PBMT had greater effects in reducing joint pain intensity, active knee flexion, physical function and muscle strength, especially in the quadriceps femoris, than strength training alone in patients with KOA.

Adjunctive electrophysical therapies used in addition to land-based exercise therapy for osteoarthritis of the hip or knee: A systematic review and meta-analysis

“…For this review, 36 studies, which investigated adjunctive EPTs were retained, and searches (using the original search strategy ( Supplementary file 1 ) rerun across the six databases in November 2022 and updated in October 2023. Following screening of 3516 titles and abstracts by two review authors (HPF and SA), 37 were retained for full-text screening and six studies were included in this review [ 11 , [19] , [20] , [21] , [22] , [23] ], along with the original 36 EPT trials from the Cochrane review [ 5 ]. Of these newly included studies, one reported different outcomes [ 21 ] from a trial previously included in the Cochrane review [ 24 ].…”

“…All studies, except one, which was a quasi-randomised trial [ 25 ], were RCTs and all trials employed a parallel group design. Nineteen studies compared the adjunctive EPT plus exercise therapy to a placebo EPT and exercise [ [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] ], whilst 22 compared against exercise only [ 9 , 11 , 19 , 20 , 22 , [34] , [35] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [57] ].…”

“…Seventeen trials compared two groups [ 11 , 23 , 25 , [28] , [29] , [30] , 33 , 36 , 39 , 41 , [43] , [44] , [45] , 48 , 49 , 54 ], 15 included three groups [ 9 , 19 , 20 , 22 , 27 , 31 , 34 , 37 , 38 , 40 , 46 , 47 , 51 , 55 , 56 ], five compared four groups [ 21 , 24 , 42 , 50 , 52 ], one compared five groups [ 57 ] and one trial had six different arms, comparing three EPTs to placebo counterparts [ 26 ]. The number of groups eligible for inclusion is shown in Table 1 , with two groups included in 27 studies [ 11 , 19 , 20 , [23] , [24] , [25] , 28 , 30 , 33 , 36 , 39 , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , 53 , 54 , 57 , …”

“…If further data were required, study authors were contacted a maximum of three times via email. We used graph digitisation software ( https://automeris.io/WebPlotDigitizer/ ) to extrapolate means and SDs by digitalising data points on graphs in two studies [ 9 , 11 ].…”

Differences in the Effectiveness of Infrared Therapy for Reducing Musculoskeletal Pain in the Elderly

“…The results of this study have been proven in many previous studies that infrared can reduce pain in the musculoskeletal system, such as in cases of tempromandibular disease pain, osteoarthritis, low back pain (LBP), knee pain, and others [17][18][19][20][21][22][23] . Even various other conditions can be treated with infrared therapy by combining it with other therapies such as muscle training, acupuncture, and others [19][20][21][22][23][24] . Other health problems that can be treated with infrared besides the musculoskeletal system are mantle cell lymphoma (MCL), comfort in turkeys, and finding difficult veins in children and the elderly [25][26][27] .…”