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

Abstract

Background: Repetitive strain injuries caused by repetitive occupational work are difficult to prevent for multiple reasons. Therefore, we examined the effectiveness of manual therapy (MT) with rest to treat the inflammation and fibrosis that develops through the performance of a repetitive task. We hypothesized that this treatment would reduce task-induced sensorimotor declines and neuromuscular inflammation.Methods: Twenty-nine female Sprague-Dawley rats performed a reaching and lever-pulling task for 14weeks. All ceased performing the task at 14weeks. Ten were euthanized at this timepoint (TASK). Nine received manual therapy to their upper extremities while resting 7weeks (MTR); 10 were assigned to rest alone (REST). Ten additional food restricted rats were included that neither performed the task nor received manual therapy (FRC).Results: Confirming previous experiments, TASK rats showed behavioral changes (forepaw mechanical hypersensitivity, reduced grip strength, lowered forelimb/forepaw agility, and noxious cold temperature sensitivity), reduced median nerve conduction velocity (NCV), and pathological tissue changes (myelin degradation, increased median nerve and muscle inflammation, and collagen production). Manual therapy with rest (MTR) ameliorated cold sensitivity seen in REST rats, enhanced muscle interleukin 10 (IL-10) more than in REST rats, lead to improvement in most other measures, compared to TASK rats. REST rats showed improved grip strength, lowered nerve inflammation and degraded myelin, and lowered muscle tumor necrosis factor alpha (TNFα) and collagen I levels, compared to TASK rats, yet maintained lowered forelimb/forepaw agility and NCV, and increased neural fibrosis.Conclusion: In our model of repetitive motion disorder, manual therapy during rest had modest effects on behavioral, histological, and physiological measures, compared to rest alone. These findings stand in contrast to the robust preventive effects of manual therapy in this same model.

Manual Therapy Facilitates Homeostatic Adaptation to Bone Microstructural Declines Induced by a Rat Model of Repetitive Forceful Task

“…We also added direct manipulation of the palm in this study, where the tip of the rat’s index finger was pressed into the palm at and just distal to the transverse carpal ligament with a rolling motion. The individuals providing these treatments were the same as in previous studies [ 19 , 20 ]. Treatments to TASK-MT rats were performed 3 times per week on alternate days to the task performance for 7 weeks and lasted approximately five to seven minutes per limb, i.e., a total of 10–14 min per rat.…”

“…GraphPad PRISM version 9 was used for the statistical analyses. The sample size for this study was derived from our previous studies [ 20 , 22 ], assuming a power of 80% and level of significance of 0.05, and a standard deviation of 28 for grip strength. All data are expressed as mean ± 95% confidence intervals (CIs).…”

“…Manual therapy (MT) is any therapy that is applied using the hands, including massage therapy and manipulative therapy. Several groups have examined the effects of various types of massage, manual therapy, or cyclical compression on functional abilities and on inflammation in soft tissues (neuromuscular tissues) in rodents and rabbits [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. For example, we found that preventive manual therapy provided concurrently with task performance reduced inflammatory responses in nerve, muscle, and tendinous tissues, as well as somatosensory hypersensitivity, pathological neural discharge, and motor declines that develop with prolonged performance of intensive repetitive upper extremity tasks [ 19 , 21 , 22 ].…”

Preliminary investigation on the effect of extracorporeal shock wave combined with traction on joint contracture based on PTEN‐PI3K/AKT pathway

“…Manual traction improves the ROM and flexibility with a relaxing position, which is characterized by the relaxation of surrounding tissues as much as possible and the largest space in the capsule 24,25 . Manual traction improves neuromuscular inflammation and fibrosis of upper limbs in a rat model of repetitive strain injury 26 . There are few reports in the literature on manual traction in rat knee contracture model.…”

The effect of tuina on ulcerative colitis model mice analyzed by gut microbiota and proteomics

“…Studies have shown that between 20 and 40% of UC patients used tuina to alleviate the unbearable symptoms ( Rawsthorne et al, 2012 ; Oxelmark et al, 2016 ). However, the effective mechanism of tuina therapy is still in its infancy, several studies found that tuina can down-regulate the expression levels of tumor necrosis factor-α, interleukin (IL)-6, and IL-10 to reduce inflammation, suggesting that tuina plays an effective role in immune or inflammatory diseases ( Mori et al, 2004 ; Crane et al, 2012 ; Negahban et al, 2013 ; Barbe et al, 2021 ). Furthermore, enrichment for diversity and beneficial bacterial community was observed in rats after tuina treatment, it is indicated that tuina exerts an immunomodulatory effect by modulating the microbiota ( Zhu et al, 2020 ).…”