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FDA Studies about Healing
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Medical Studies



1. The Role of Heat Therapy in Exercise Recovery and Muscle Rehabilitation

  • Title: Turning Up the Heat: An Evaluation of the Evidence for Heating to Promote Exercise Recovery, Muscle Rehabilitation, and Adaptation
  • Authors: Hamish McGorm, Llion A Roberts, Jeff S Coombes, Jonathan M Peake
  • Published in: Sports Medicine (2018)
  • Summary: This narrative review evaluates various heat therapy methods for muscle recovery, rehabilitation, and adaptation. The study discusses the physiological rationale behind heat therapy and its effects before, during, and after muscle injury, immobilization, and strength training. Findings suggest that heat therapy can reduce muscle damage, prevent atrophy, and promote regeneration. In humans, microwave diathermy and hot water immersion have shown benefits in mitigating muscle soreness and restoring function. However, the effectiveness of post-exercise heat therapy varies. The review highlights the need for further research to optimize heat therapy for muscle preservation, particularly in aging populations and injury recovery.
  • Link: PubMed Link


2. Hyperthermia Induced by Microwave Diathermy in the Management of Muscle and Tendon Injuries

  • Title: Hyperthermia Induced by Microwave Diathermy in the Management of Muscle and Tendon Injuries
  • Authors: A. Giombini, V. Giovannini, A. Di Cesare, P. Pacetti, Noriko Ichinoseki-Sekine, M. Shiraishi, Hisashi Naito, Nicola Maffulli
  • Published in: British Medical Bulletin (2007)
  • Summary: This study explores the effects of hyperthermia induced by microwave diathermy on muscle and tendon injuries. The technique raises deep tissue temperatures between 41°C and 45°C using electromagnetic power and has been widely used in physical medicine and sports traumatology. Research findings indicate that microwave diathermy stimulates tissue repair, enhances drug activity, alleviates pain, aids in waste removal, increases tendon extensibility, and reduces muscle and joint stiffness. The therapy also promotes hyperaemia, improves tissue drainage, accelerates metabolism, and induces cellular changes. While the exact biological mechanisms linking thermal dose to healing remain under investigation, microwave diathermy at 434 and 915 MHz has shown short-term effectiveness in managing musculoskeletal injuries.
  • Link: PubMed Link


3. Shortwave Diathermy Enhances Ankle Dorsiflexion More Than Stretching Alone

  • Title: Pulsed Shortwave Diathermy and Prolonged Long-Duration Stretching Increase Dorsiflexion Range of Motion More Than Identical Stretching Without Diathermy
  • Authors: S. E. Peres, D. O. Draper, K. L. Knight, M. D. Ricard
  • Published in: Journal of Athletic Training (2002)
  • Summary: This study investigated the effects of pulsed shortwave diathermy (PSWD) combined with stretching on ankle dorsiflexion range of motion (ROM). Forty-four college students were divided into four groups: control, stretching alone, diathermy plus stretching, and diathermy plus stretching followed by ice. Over 14 sessions spanning three weeks, participants receiving diathermy and stretching demonstrated significantly greater ROM improvements compared to those stretching alone. The benefits persisted even six days after treatment concluded, indicating that PSWD enhances the long-term effects of stretching on flexibility.
  • Link: PubMed Link


4. Effects of Far-Infrared Radiation Lamp Therapy on Recovery from Muscle Damage

  • Title: Effects of Far-Infrared Radiation Lamp Therapy on Recovery from Muscle Damage Induced by Eccentric Exercise
  • Authors: Trevor C. Chen, Yuh-Chuan Huang, Tai-Ying Chou, Sheng-Tsung Hsu, Mei-Yen Chen, Kazunori Nosaka
  • Published in: European Journal of Sport Science (2023)
  • Summary: This study examined the effects of far-infrared radiation (FIR) lamp therapy on muscle damage and proprioception following eccentric exercise of the elbow and knee flexors. In a controlled experiment, 24 sedentary women received either FIR therapy or a sham treatment. The FIR group showed significantly faster recovery in muscle strength and proprioception, reduced muscle soreness by 55-60%, and lowered peak plasma creatine kinase activity by 45-89%. FIR therapy accelerated recovery from exercise-induced muscle damage more effectively than previously studied interventions.
  • Link: PubMed Link


5. Far-Infrared Radiation and Its Therapeutic Parameters in Regenerative Medicine

  • Title: Far-Infrared Radiation and Its Therapeutic Parameters: A Superior Alternative for Future Regenerative Medicine?
  • Authors: Bo Qin, Shi-Jie Fu, Xiong-Fei Xu, Jiu-Jie Yang, Yuping Wang, Lin-Na Wang, Bai-Xiong Huang, Jing Zhong, Wan-Yu Wu, Heng-Ao Lu, Betty Yuen Kwan Law, Nick Wang, Io Nam Wong, Vincent Kam Wai Wong
  • Published in: Pharmacological Research (2024)
  • Summary: This review explores the potential of far-infrared radiation (FIR) as an essential component of future regenerative medicine. It systematically outlines FIR's therapeutic parameters—wavelength range, power density, irradiation time, and distance—while examining its biological effects and molecular mechanisms. The study highlights the therapeutic potential of FIR in various diseases, emphasizing its ability to influence cellular processes and enhance tissue regeneration. Despite its promising applications, the lack of standardized parameters limits widespread clinical adoption. The review suggests that FIR could become a superior alternative therapy in regenerative medicine.
  • Link: PubMed Link


6. Continuous Short-Wave (Radio-Frequency) Diathermy

  • Title: Continuous Short-Wave (Radio-Frequency) Diathermy
  • Authors: G. C. Goats
  • Published in: British Journal of Sports Medicine (1989)
  • Summary: This study examines the use of continuous shortwave diathermy (SWD) as a method for achieving uniform deep tissue heating. It highlights that continuous SWD is effective in treating sub-acute or chronic conditions by promoting vasodilation, reducing swelling, and increasing joint range of motion. The study also notes that acute injuries respond better to pulsed SWD. The findings suggest that continuous SWD can relieve pain and muscle spasms while improving connective tissue compliance and reducing joint stiffness, making it comparable to ultrasound therapy.
  • Link: PubMed Link


7. The Effect of Microwave Therapy on Muscle Blood Flow

  • Title: The Effect of Microwave Therapy Upon Muscle Blood Flow in Man
  • Authors: D. J. Wyper, D. R. McNiven
  • Published in: British Journal of Sports Medicine (1976)
  • Summary: This study measured muscle blood flow using a radioactive tracer technique in five healthy subjects. Researchers found that microwave therapy at 2450 MHz significantly increased muscle blood flow compared to resting values. The mean blood flow increased from 2.9 ml/100g/min at rest to 11.4 ml/100g/min during microwave therapy. The study concluded that microwave therapy has a greater effect on muscle blood flow than other therapeutic modalities, highlighting its potential benefits for tissue perfusion and recovery.
  • Link: PubMed Link


8. Preconditioning with Hyperthermia to Reduce Exercise-Induced Muscle Damage

  • Title: Preconditioning with Whole-Body or Regional Hyperthermia Attenuates Exercise-Induced Muscle Damage in Rodents
  • Authors: T. Mikami, H. Yamauchi
  • Published in: Physiological Research (2022)
  • Summary: This study investigated whether hyperthermia before exercise could protect against exercise-induced muscle damage. Two preconditioning methods were evaluated in rodents: whole-body heat exposure (42°C for 30 min) and regional heating of the legs using microwave diathermy. Both methods significantly increased HSP70 and HSP25 levels in the soleus muscle. Muscle damage markers, including plasma creatine kinase and beta-glucuronidase, were lower in heat-exposed rodents than in controls. Histological analysis confirmed reduced muscle damage. These findings suggest that pre-exercise hyperthermia, including microwave diathermy, enhances muscle protection by increasing heat shock proteins and reducing structural damage.
  • Link: PubMed Link


9. Shortwave and Microwave Diathermy for Nerve Regeneration

  • Title: Role of Shortwave and Microwave Diathermy in Peripheral Neuropathy
  • Authors: T. Fu, W.C. Lineaweaver, F. Zhang, J. Zhang
  • Published in: Journal of International Medical Research (2019)
  • Summary: This review analyzed the effects of shortwave and microwave diathermy on nerve regeneration in both animal models and human patients. Animal studies showed that diathermy improved nerve healing by increasing the number of myelinated fibers, myelin sheath thickness, and axon diameter, leading to better nerve function. In clinical studies involving 128 patients with carpal tunnel syndrome, diathermy was associated with reduced pain, improved hand function, and better electrophysiological outcomes. These findings suggest that shortwave and microwave diathermy may be beneficial for peripheral nerve repair.
  • Link: PubMed Link


10. Effects of Heat, Cold, and Pressure on the Transverse Carpal Ligament and Median Nerve

  • Title: Effect of Heat, Cold, and Pressure on the Transverse Carpal Ligament and Median Nerve: A Pilot Study
  • Authors: Michael Laymon, Jerrold Petrofsky, James McKivigan, Haneul Lee, JongEun Yim
  • Published in: Medical Science Monitor (2015)
  • Summary: This pilot study investigated the effects of heat, cold, and pressure on the median nerve and transverse carpal ligament in healthy individuals. Using ultrasound imaging, researchers assessed ligament elasticity, nerve conduction velocity, and structural changes. Heat therapy (60-120 minutes) increased ligament and tendon elasticity, while cold exposure (20 minutes) reduced compression of the carpal ligament and nerve. Pressure did not significantly alter tissue structure at room temperature or after cold exposure. The findings suggest that heat enhances tissue flexibility, whereas cold may help reduce compression in conditions like carpal tunnel syndrome.
  • Link: PubMed Link


11. Shortwave Diathermy Enhances Hamstring Flexibility

  • Title: Shortwave Diathermy and Prolonged Stretching Increase Hamstring Flexibility More Than Prolonged Stretching Alone
  • Authors: D.O. Draper, J.L. Castro, B. Feland, S. Schulthies, D. Eggett
  • Published in: Journal of Orthopaedic & Sports Physical Therapy (2004)
  • Summary: This study examined whether shortwave diathermy enhances hamstring flexibility when combined with stretching. Thirty college students with tight hamstrings were divided into three groups: (1) diathermy plus stretching, (2) sham diathermy plus stretching, and (3) control. After five days, the diathermy group improved knee extension by 15.8°, significantly more than the sham group (5.2°) and the control (-0.3°). Flexibility gains were better maintained in the diathermy group. These results suggest that combining shortwave diathermy with stretching is an effective method to improve and sustain hamstring flexibility.
  • Link: PubMed Link


12. Shortwave Diathermy Enhances Recovery in Lateral Epicondylitis

  • Title: Continuous Shortwave Diathermy with Exercise Reduces Pain and Improves Function in Lateral Epicondylitis More Than Sham Diathermy: A Randomized Controlled Trial
  • Authors: A. Babaei-Ghazani, B. Shahrami, E. Fallah, T. Ahadi, B. Forough, S. Ebadi
  • Published in: Journal of Bodywork & Movement Therapies (2020)
  • Summary: This study evaluated the effectiveness of continuous shortwave diathermy (SWD) in treating chronic lateral epicondylitis (tennis elbow). Fifty patients were assigned to either an SWD + exercise group or a sham diathermy + exercise group. The SWD group received 15 minutes of 40-60 W continuous SWD along with specific exercises. Pain, function, and grip strength were measured at baseline, after 5 and 10 treatment sessions, and at 3 months. The SWD group showed significantly greater improvements in all outcomes compared to the control group. These findings suggest that SWD enhances pain relief and functional recovery in lateral epicondylitis.
  • Link: PubMed Link


13. Low-Intensity Pulsed Ultrasound Stimulation for Tendon-Bone Healing

  • Title: Low-Intensity Pulsed Ultrasound Stimulation for Tendon-Bone Healing: A Dose-Dependent Study
  • Authors: Hongbin Lu, Fei Liu, Can Chen, Zhanwen Wang, Huabin Chen, Jin Qu, Tao Zhang, Daqi Xu, Jianzhong Hu
  • Published in: American Journal of Physical Medicine & Rehabilitation (2018)
  • Summary: This study examined the effects of different dosages of low-intensity pulsed ultrasound (LIPUS) on tendon-bone healing in rabbits. Three groups were compared: a control group (no ultrasound), a once-daily (qd) treatment group, and a twice-daily (bid) treatment group. Results showed that the bid group exhibited significantly greater new bone formation, mineralization, fibrocartilage development, and improved mechanical properties at the healing site compared to the other groups. Findings suggest that twice-daily LIPUS treatment is more effective for enhancing tendon-bone healing than a once-daily treatment.
  • Link: PubMed Link


14. Effect of Manual Therapy and Neurodynamic Techniques vs Ultrasound and Laser on Two-Point Discrimination in CTS

  • Title: Effect of Manual Therapy and Neurodynamic Techniques vs Ultrasound and Laser on 2PD in Patients with CTS: A Randomized Controlled Trial
  • Authors: Tomasz Wolny, Edward Saulicz, Paweł Linek, Andrzej Myśliwiec, Mariola Saulicz
  • Published in: Journal of Hand Therapy (2016)
  • Summary: This randomized controlled trial investigated the effects of manual therapy and neurodynamic techniques versus ultrasound and laser therapy on two-point discrimination (2PD) in carpal tunnel syndrome (CTS) patients. Participants were divided into two groups: one received neurodynamic mobilization and manual therapy, while the other underwent electrophysical modalities (red/infrared laser and ultrasound). After 20 therapy sessions over 10 weeks, both groups showed significant improvement in 2PD in symptomatic hands (p < .001). However, no statistically significant difference was observed between the two treatments, indicating that both approaches were equally effective in improving sensory function in CTS patients.
  • Link: PubMed Link


15. Collagen Shortening: An Experimental Approach with Heat

  • Title: Collagen Shortening: An Experimental Approach with Heat
  • Authors: C.T. Vangsness Jr, W. Mitchell 3rd, M. Nimni, M. Erlich, V. Saadat, H. Schmotzer
  • Published in: Clinical Orthopaedics and Related Research (1997)
  • Summary: This in vitro study investigated the effects of heat on human collagen, specifically its ability to shrink and its mechanical and histological changes. Fresh frozen human tendons were subjected to heat in a saline solution, demonstrating a predictable shrinkage curve. A sharp increase in shrinkage (up to 70% of the original length) was observed around 70°C. Additionally, an Nd:YAG laser was used to induce precise, dose-dependent collagen shortening. Tendons shortened by 10% exhibited a significant decrease in load-to-failure strength (to about one-third of control specimens). Histological analysis revealed distinct thermal denaturation zones while preserving adjacent collagen. These findings suggest that collagen can be precisely shortened using heat, though further research is needed to assess biological responses, including recollagenization and long-term biomechanical effects.
  • Link: PubMed Link


16. Effect of Heat and Cold on Tendon Flexibility and Force to Flex the Human Knee

  • Title: Effect of Heat and Cold on Tendon Flexibility and Force to Flex the Human Knee
  • Authors: Jerrold Scott Petrofsky, Michael Laymon, Haneul Lee
  • Published in: Medical Science Monitor (2013)
  • Summary: This study quantified the effects of heat and cold on knee tendon flexibility and the force required to flex the knee. Twenty male and female subjects participated in four experimental conditions: (1) room temperature, (2) cold application (ice pack for 20 min), (3) heat application (hydrocollator heat packs for 20 min), and (4) prolonged heat application (ThermaCare heat wraps for 4 hours). Ligament extensibility was measured using a KT2000 arthrometer, and the force required for knee flexion was assessed using continuous passive motion (CPM). Results showed that heat increased the flexibility of the anterior and posterior cruciate ligaments and reduced the force required for knee flexion by about 25%, while cold had the opposite effect. These findings suggest that heat therapy may enhance flexibility and reduce injury risk, whereas cold therapy may restrict movement.
  • Link: PubMed Link


17. Infrared Laser Improves Collagen Organization in Muscle & Tendon Tissue

  • Title: Infrared Laser Improves Collagen Organization in Muscle and Tendon Tissue During the Process of Compensatory Overload
  • Authors: S.M.L. Terena, K.P.S. Fernandes, S.K. Bussadori, et al.
  • Published in: Photomedicine and Laser Surgery (2018)
  • Summary: This study examined the effects of infrared laser therapy (LLLT) on collagen deposition and organization in muscle and tendon tissue during compensatory overload in rats. After the removal of synergist muscles, animals were divided into control, hypertrophy, and hypertrophy + LLLT groups. Infrared laser therapy (780 nm, 40 mW) was applied daily. At 7 days, treated muscles showed increased collagen content and better fiber organization. At 14 days, collagen levels decreased in muscle, while tendon fibers remained well-organized. These findings suggest that LLLT helps regulate collagen remodeling, potentially aiding recovery from muscle overload.
  • Link: PubMed Link


18. Far-Infrared Radiation Reduces Pain & Aids Early Recovery After Rotator Cuff Repair

  • Title: The Effect of Postoperatively Applied Far-Infrared Radiation on Pain and Tendon-to-Bone Healing After Arthroscopic Rotator Cuff Repair
  • Authors: J.Y. Yoon, J.H. Park, K.J. Lee, et al.
  • Published in: Korean Journal of Pain (2020)
  • Summary: This randomized study evaluated the effects of far-infrared radiation (FIR) therapy on pain and healing after arthroscopic rotator cuff repair in 38 patients with medium-sized tears. The FIR group received twice-daily 30-minute FIR sessions from week 1 to week 5 post-surgery. At 5 weeks, FIR patients reported significantly lower pain scores (1.5 vs. 2.7, P = 0.019) and greater shoulder flexion at 3 months (151.6° vs. 132.9°, P = 0.045). By 6 months, ROM and healing rates were similar between groups. FIR may be a safe and effective method to reduce early postoperative pain and enhance rehabilitation.
  • Link: PubMed Link


19. Far-Infrared Radiation Reduces Pain After Rotator Cuff Repair

  • Title: Far-Infrared Radiation to Improve Clinical Outcomes After Arthroscopic Rotator Cuff Repair: A Prospective Randomized Comparative Clinical Study
  • Authors: J.H. Park, J.Y. Yoon, M.G. Jeong, et al.
  • Published in: Clinical Orthopaedic Surgery (2023)
  • Summary: This randomized study examined the effects of far-infrared radiation (FIR) therapy on pain, range of motion (ROM), and healing after arthroscopic rotator cuff repair in 64 patients. The FIR group received twice-daily 30-minute FIR sessions for 10 weeks. At 5 weeks and 3 months post-surgery, FIR patients reported significantly lower pain scores (1.7 vs. 2.8, P = 0.002 at 5 weeks; 2.4 vs. 3.2, P = 0.041 at 3 months). However, ROM, functional scores, and healing rates showed no significant differences between groups. FIR may be a safe and effective method to reduce early postoperative pain and support rehabilitation.
  • Link: PubMed Link


20. Shortwave Diathermy Increases Blood Flow and Skin Temperature in Lower Limbs

  • Title: Application of Shortwave Diathermy to Lower Limb Increases Arterial Blood Flow Velocity and Skin Temperature in Women: A Randomized Controlled Trial
  • Authors: N. T. A. De Sousa, E. C. O. Guirro, J. G. Calió, M. C. De Queluz, R. R. De Jesus Guirro
  • Published in: Brazilian Journal of Physical Therapy (2017)
  • Summary: This randomized controlled trial examined the effects of shortwave diathermy (SWD) and microwave diathermy (MWD) on blood flow and skin temperature in the lower limbs of healthy women. Forty participants received 20 minutes of either SWD or MWD to the posterior thigh and leg. Measurements taken before, immediately after, and at 10 and 20 minutes post-treatment showed that SWD significantly increased arterial blood flow velocity and sustained skin temperature elevation for at least 20 minutes. MWD also increased skin temperature but had no significant effect on blood flow. These findings highlight SWD’s potential for improving circulation and tissue heating.
  • Link: PubMed Link


21. Low-Level Laser Therapy Effectively Treats Tennis and Golfer’s Elbow

  • Title: Treatment of Medial and Lateral Epicondylitis—Tennis and Golfer's Elbow—With Low-Level Laser Therapy: A Multicenter Double-Blind, Placebo-Controlled Clinical Study on 324 Patients
  • Authors: Z. Simunovic, T. Trobonjaca, Z. Trobonjaca
  • Published in: Journal of Clinical Laser Medicine & Surgery (1998)
  • Summary: This multicenter, double-blind, placebo-controlled study evaluated the effectiveness of low-level laser therapy (LLLT) in 324 patients with medial (n=50) or lateral (n=274) epicondylitis. Patients received either trigger point laser therapy, scanner-based laser therapy, or a combination of both. The combination treatment resulted in complete pain relief and improved functional ability in 82% of acute and 66% of chronic cases. The study highlights the importance of proper dosing, technique, and therapist expertise in optimizing LLLT outcomes for epicondylitis.
  • Link: PubMed Link


22. Low-Level Laser Therapy Improves Symptoms of Fibromyalgia

  • Title: Low-Level Laser Therapy for Fibromyalgia: A Systematic Review and Meta-Analysis
  • Authors: S.-W. Yeh, C.-H. Hong, M.-C. Shih, K.-W. Tam, Y.-H. Huang, Y.-C. Kuan
  • Published in: Pain Physician (2019)
  • Summary: This systematic review and meta-analysis evaluated the efficacy of low-level laser therapy (LLLT) in treating fibromyalgia. Nine randomized controlled trials (RCTs) including 325 patients were analyzed. Compared to placebo, LLLT significantly improved Fibromyalgia Impact Questionnaire (FIQ) scores, pain severity, number of tender points, fatigue, stiffness, anxiety, and depression. However, when LLLT was combined with a standardized exercise program, it did not show additional benefits over exercise alone. A separate RCT using combined LLLT/LED phototherapy demonstrated further improvements in most outcomes. Despite some methodological limitations, the findings suggest LLLT is an effective and well-tolerated treatment for fibromyalgia.
  • Link: PubMed Link


23. Low-Level Laser Therapy Provides Short-Term Pain Relief for Chronic Low Back Pain

  • Title: Low-Level Laser Therapy for Chronic Non-Specific Low Back Pain: A Meta-Analysis of Randomised Controlled Trials
  • Authors: G. Glazov, M. Yelland, J. Emery
  • Published in: Acupuncture in Medicine (2016)
  • Summary: This meta-analysis reviewed 15 randomized controlled trials involving 1,039 participants to evaluate the efficacy of low-level laser therapy (LLLT) for chronic non-specific low back pain (CNLBP). Results showed a significant short-term reduction in pain, particularly in studies using at least 3 Joules per point and in patients with pain lasting less than 30 months. Global assessment of improvement also favored laser therapy at immediate follow-up. However, the benefits were only observed in trials that did not use an acupuncture-based laser approach. The study concludes that LLLT may provide short-term relief for CNLBP, but further high-quality, blinded trials are needed to confirm its effectiveness.
  • Link: PubMed Link