Soft Tissue Manipulation May Attenuate Inflammation, Modulate Pain, and Improve Gait in Conscious Rodents With Induced Low Back Pain

Abstract

Introduction Low back pain (LBP) is common in warfighters. Noninvasive interventions are necessary to expedite return-to-function. Soft tissue manipulation, for example, massage, is a method used to treat LBP. Instrument-assisted soft tissue manipulation (IASTM) uses a rigid device to mobilize the tissue. This study explored the effects of IASTM on pain, function, and biomarkers. Methods Sprague-Dawley rats (n = 44) were randomized to groups (n = 6/grp): (A) cage control; (B) 3 days (3d) postinjury (inj), untreated; (C) 3d inj, < 30-minute post-IASTM treatment; (D) 3d inj, 2 hours (2h) post-IASTM; (E) 14 days (14d) inj, untreated; (F) 14d inj, < 30-minute post-IASTM; and (G) 14d inj, 2h post-IASTM. Researchers induced unilateral LBP in Sprague-Dawley rats using complete Freund’s adjuvant injection. Conscious rodents received IASTM for 5 min/session once at 3 days or 3×/week × 2weeks (6× total) over 14 days. Biomarker plasma levels were determined in all groups, while behavioral outcomes were assessed in two groups, D and G, at three time points: before injury, pre-, and post-IASTM treatment. Circulating mesenchymal stem cell levels were assessed using flow cytometry and cytokine plasma levels assayed. Results The back pressure pain threshold (PPT) lowered bilaterally at 3 days postinjury (P < .05), suggesting increased pain sensitivity. IASTM treatment lowered PPT more on the injured side (15.8%; P < 0.05). At 14 days, back PPT remained lower but similar side to side. At 3 days, paw PPT increased 34.6% in the contralateral rear limb following treatment (P < .01). Grip strength did not vary significantly. Gait coupling patterns improved significantly (P < .05). Circulating mesenchymal stem cell levels altered significantly postinjury but not with treatment. Neuropeptide Y plasma levels increased significantly at 3 days, 2h post-IASTM (53.2%) (P < .05). Interleukin-6 and tumor necrosis factor-alpha did not vary significantly. At 14 days, regulated on activation, normal T cell expressed and secreted decreased significantly <30-minute post-IASTM (96.1%, P < .002), while IL-10 trended upward at 2h (53.1%; P = .86). Conclusions LBP increased pain sensitivity and diminished function. IASTM treatment increased pain sensitization acutely in the back but significantly reduced pain sensitivity in the contralateral rear paw. Findings suggest IASTM may positively influence pain modulation and inflammation while improving gait patterns. Soft tissue manipulation may be beneficial as a conservative treatment option for LBP.

A call for research on soft tissue manipulation (STM) as a bone anabolic therapy

“…Additionally, conditioned medium from fibroblasts subjected to STM-like stimulation promotes differentiation of satellite cells into skeletal muscle myocytes 31 . For certain pro-inflammatory mediators such as IL-6 and IL-8, these in vitro studies are remarkably consistent with the reduction in IL-6 or IL-8 levels observed after massage therapy in humans (soft tissue biopsies 32 and plasma 33 ) and rats (sera 34 ).…”

Manual Therapy With Rest as a Treatment for Established Inflammation and Fibrosis in a Rat Model of Repetitive Strain Injury

“…Others have published similar results using other force-based methods. Using a method designed to emulate cross-fiber massage, treatment augmented pain induced by experimental subcutaneous inflammation ( Loghmani et al, 2021 ). A robot-assisted mechanical therapy resembling deep tissue therapy was shown to prevent behavioral and histological markers of muscle damage following experimental stroke ( Sen et al, 2017 ).…”

A Handheld Quantifiable Soft Tissue Manipulation Device for Tracking Real-Time Dispersive Force-Motion Patterns to Characterize Manual Therapy Treatment

“…Eq. (3)(4)(5) explains the quaternion to Euler angle conversions to estimate real-time orientation angles of the device [27][28].…”

“…Soft Tissue Manipulation (STM) [ 2 ], [ 3 ], a non-invasive force-based intervention, constitutes an integral part of manual therapy which facilitates treatment of NMSK conditions. It enables a therapist to manually palpate and locate soft tissue restrictions or scar tissues and treat them with externally applied forces in linear or curvilinear fashion, shown to remediate inflammation [ 4 ] and enhance blood flow and vascularity. With the current state-of-the-art STM practice, palpation and treatment are performed either by hand only or using tools made of steel or wood for Instrument-Assisted Soft Tissue Manipulation (IASTM).…”