Effects of alternating heat and cold stimulation using a wearable thermo-device on subjective and objective shoulder stiffness

Mechanisms and Efficacy of Contrast Therapy for Musculoskeletal Painful Disease: A Scoping Review

Background: Contrast therapy (CT) is a non-pharmacological treatment that alternates between cryotherapy and thermotherapy. It helps reduce VAS pain, improve joint ROM, enhance function, alleviate muscle soreness, and manage swelling, while also improving blood circulation. This scoping review summarizes recent studies on its use for musculoskeletal injuries (e.g., exercise-induced muscle damage, ankle sprain), degenerative conditions (e.g., osteoarthritis), and painful disorders (e.g., complex regional pain syndrome), assessing its healing potential compared to other conservative therapies. Methods: PubMed, Scopus, and Cochrane Library were searched to identify relevant publications. Articles were selected using the following inclusion criteria: randomized controlled trials, written in English, published between 2004 and 2024, and addressing the use of CT in the management of musculoskeletal painful conditions. Results: Data from 7 articles and 303 patients with musculoskeletal painful conditions treated with CT were included. There was considerable heterogeneity in terms of treatment protocols, with significant differences in the application method, duration, sequence of individuals in each hot/cold cycle, total treatment time, and the pathologies studied. Nevertheless, all studies showed an improvement in the patients' initial clinical conditions. Conclusions: This review highlights the lack of guidelines for the clinical use of CT in musculoskeletal painful conditions. The heterogeneity of the studies reviewed (different clinical scores, follow-up periods, data, and samples) makes the results imprecise. In addition, the modest quality of the trials does not allow the authors to draw clear conclusions about the effectiveness of CT compared with other therapies.

Investigation of Choroidal Circulation Hemodynamics Using Laser Speckle Flowgraphy After Periocular Skin Warming

PURPOSE

The aim of the current study was to evaluate changes in choroidal circulation hemodynamics after periocular skin warming at 40°C using laser speckle flowgraphy (LSFG).

METHODS

Twenty-four right eyes of 24 healthy participants were included. Changes in choroidal circulation hemodynamics were determined using LSFG to evaluate the mean blur rate (MBR) of the macula, which represents choroidal blood flow velocity. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), heart rate (HR), ocular perfusion pressure (OPP), and subfoveal choroidal thickness (SCT) were also measured, and sympathetic nerve status was assessed via salivary α-amylase (sAA) activity at baseline and after periocular skin warming.

RESULTS

Immediately after warming, SBP, DBP, MBP, HR, OPP, sAA activity, and MBR were significantly lower than baseline. SCT was significantly increased.

CONCLUSION

In the normal eye, the decrease in sympathetic nerve activity induced by the relaxing effects of periocular skin warming reduces systemic circulatory activity and choroidal circulatory dynamics.

Comparison of the effects of three different resistance training methods on muscle fatigue in healthy untrained men

Introduction

Traditional set (TS), paired-set (PS), and super-set (SS) are used as resistance training methods. However, the effects of these methods on muscle fatigue (muscle strength and training volume) are not clear. The purpose of this study was to compare the effects of TS, PS, and SS on the muscle fatigue of the hamstrings and quadriceps.

Methods

Thirteen healthy, untrained men performed three sets of leg curl and leg extension exercises. TS included three successive sets of the leg curl and leg extension exercises with a 60 s rest interval between sets and exercises. In the PS, leg curl exercises were performed alternatingly with the leg extension exercises with a 60 s rest interval between sets and exercises. In the SS, leg curl and leg extension exercises were performed alternatively with each set. During SS, a 60 s rest interval was set between sets but not between exercises. Muscle strength before and immediately after interventions, and training volume during the training, were measured using an isokinetic dynamometer machine. Time efficiency was calculated by dividing the total training volume by the time required for each intervention.

Results and discussion

The muscle strength of the hamstrings decreased in PS (p = 0.039) and SS (p = 0.001) but did not change in TS (p = 0.434). Muscle strength of the quadriceps decreased in all interventions (p < 0.05). In all interventions, the training volume of the hamstrings decreased in Set 2 (p < 0.05), and that of the quadriceps decreased in Set 3 (p < 0.05). The total training volume in PS was higher than TS (p < 0.01) and SS (p = 0.03). Time efficiency in SS was higher than TS (p < 0.01) and PS (p < 0.01). These results indicated that PS could be useful for individuals with sufficient time for resistance training because of greater training volume, while SS could be useful for those with limited time due to better time efficiency.

Optimal Duration of Cold and Heat Compression for Forearm Muscle Biomechanics in Mixed Martial Arts Athletes: A Comparative Study

BACKGROUND Cold and heat therapies for recovery in sports are commonly used, including in the mixed martial arts (MMA). The Game Ready (GR) device can be used for local monotherapy with either heat or cold and for contrast therapy. This study aimed to compare the effects of duration of cold and heat compression on biomechanical changes in the forearm muscles of 20 healthy mixed martial arts athletes. MATERIAL AND METHODS Twenty MMA volunteers (26.5±4.5 years old) underwent 3 different phases of the GR: (1) stimulation time 10 min (eGR-10, GR experimental group), (2) 10 min (cGR-10, sham control group) and (3) 20 min (eGR-20, GR experimental group). The following outcomes were assessed: muscle tone (T), stiffness (S), flexibility (E), pressure pain threshold (PPT), microvascular response (PU), and maximum isometric strength (Fmax). All measurements were performed before GR (rest) and after GR stimulation (post). RESULTS Both eGR-10 and eGR-20 significantly improved outcomes T (p<0.001), S (p<0.001), E (p=0.001, and p<0.001, respectively), PPT (p<0.001), PU (p<0.001), and Fmax (p<0.001). Notably, eGR-20 exhibited superior improvements in PU, Fmax, and PPT, with larger effect sizes (p<0.001). While eGR-10 demonstrated more pronounced reductions in T and S (p<0.001), these results underscore the potential for tailored GR therapy durations to optimize specific recovery goals for MMA athletes. CONCLUSIONS GR stimulation affects muscle biomechanical changes, pain threshold, muscle strength, and tissue perfusion. The study results suggest that 10 min of GR stimulation is sufficient to achieve changes that can be used to optimize recovery for MMA athletes.

Local alternating heat and cold stimulation affects hemodynamics and oxygenation in fatigued muscle tissue and autonomic nervous activity: a single-arm interventional study

BACKGROUND

Local alternating heat and cold stimulation as an alternative to contrast bath may cause intermittent vasoconstriction and vasodilation, inducing a vascular pumping effect and consequently promoting increased tissue blood flow and oxygenation. This study aimed to examine the effects of local alternating heat and cold stimulation, using a wearable thermal device, on the hemodynamics of fatigued muscle tissue and autonomic nervous activity.

METHODS

Twenty healthy individuals experienced fatigue in the periarticular muscles of the shoulder joint due to a typing task. Local alternating heat and cold stimulations were then applied to the upper trapezius muscle. Muscle hardness was measured using a muscle hardness meter, and muscle tissue hemodynamics and oxygenation were evaluated using near-infrared spectroscopy before and after the stimulation. Autonomic nervous activity was also evaluated using heart rate variability.

RESULTS

Alternating heat and cold stimulation decreased muscle hardness of the fatigued trapezius muscle from 1.38 ± 0.15 to 1.31 ± 0.14 N (P < 0.01). The concentration of total hemoglobin in the trapezius muscle tissue increased from - 0.21 ± 1.36 to 2.29 ± 3.42 µmol/l (P < 0.01), and the tissue hemoglobin oxygen saturation also increased from 70.1 ± 5.4 to 71.1 ± 6.0% (P < 0.05). Additionally, the heart rate variability parameter, which is an index of sympathetic nervous activity, increased from 3.82 ± 2.96 to 6.86 ± 3.49 (P < 0.01). A correlation was found between increased tissue hemoglobin oxygen saturation and increased parameters of sympathetic nervous activity (r = 0.50, P < 0.05).

CONCLUSIONS

Local alternating heat and cold stimulation affected the hemodynamic response in fatigued muscle tissue and autonomic nervous activity. This stimulation is more efficient than conventional contrast baths in terms of mobility and temperature control and has potential as a new versatile therapeutic intervention for muscle fatigue.

TRIAL REGISTRATION

UMIN-CTR (UMIN000040087: registered on April 7, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045710 . UMIN000040620: registered on June 1, 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359 ).

Exercise therapy for tendinopathy: a mixed-methods evidence synthesis exploring feasibility, acceptability and effectiveness

Background

Tendinopathy is a common, painful and functionally limiting condition, primarily managed conservatively using exercise therapy.

Review questions

(i) What exercise interventions have been reported in the literature for which tendinopathies? (ii) What outcomes have been reported in studies investigating exercise interventions for tendinopathy? (iii) Which exercise interventions are most effective across all tendinopathies? (iv) Does type/location of tendinopathy or other specific covariates affect which are the most effective exercise therapies? (v) How feasible and acceptable are exercise interventions for tendinopathies?

Methods

A scoping review mapped exercise interventions for tendinopathies and outcomes reported to date (questions i and ii). Thereafter, two contingent systematic review workstreams were conducted. The first investigated a large number of studies and was split into three efficacy reviews that quantified and compared efficacy across different interventions (question iii), and investigated the influence of a range of potential moderators (question iv). The second was a convergent segregated mixed-method review (question v). Searches for studies published from 1998 were conducted in library databases (n = 9), trial registries (n = 6), grey literature databases (n = 5) and Google Scholar. Scoping review searches were completed on 28 April 2020 with efficacy and mixed-method search updates conducted on 19 January 2021 and 29 March 2021.

Results

Scoping review - 555 included studies identified a range of exercise interventions and outcomes across a range of tendinopathies, most commonly Achilles, patellar, lateral elbow and rotator cuff-related shoulder pain. Strengthening exercise was most common, with flexibility exercise used primarily in the upper limb. Disability was the most common outcome measured in Achilles, patellar and rotator cuff-related shoulder pain; physical function capacity was most common in lateral elbow tendinopathy. Efficacy reviews - 204 studies provided evidence that exercise therapy is safe and beneficial, and that patients are generally satisfied with treatment outcome and perceive the improvement to be substantial. In the context of generally low and very low-quality evidence, results identified that: (1) the shoulder may benefit more from flexibility (effect sizeResistance:Flexibility = 0.18 [95% CrI 0.07 to 0.29]) and proprioception (effect sizeResistance:Proprioception = 0.16 [95% CrI -1.8 to 0.32]); (2) when performing strengthening exercise it may be most beneficial to combine concentric and eccentric modes (effect sizeEccentricOnly:Concentric+Eccentric = 0.48 [95% CrI -0.13 to 1.1]; and (3) exercise may be most beneficial when combined with another conservative modality (e.g. injection or electro-therapy increasing effect size by ≈0.1 to 0.3). Mixed-method review - 94 studies (11 qualitative) provided evidence that exercise interventions for tendinopathy can largely be considered feasible and acceptable, and that several important factors should be considered when prescribing exercise for tendinopathy, including an awareness of potential barriers to and facilitators of engaging with exercise, patients' and providers' prior experience and beliefs, and the importance of patient education, self-management and the patient-healthcare professional relationship.

Limitations

Despite a large body of literature on exercise for tendinopathy, there are methodological and reporting limitations that influenced the recommendations that could be made.

Conclusion

The findings provide some support for the use of exercise combined with another conservative modality; flexibility and proprioception exercise for the shoulder; and a combination of eccentric and concentric strengthening exercise across tendinopathies. However, the findings must be interpreted within the context of the quality of the available evidence.

Future work

There is an urgent need for high-quality efficacy, effectiveness, cost-effectiveness and qualitative research that is adequately reported, using common terminology, definitions and outcomes.

Study registration

This project is registered as DOI: 10.11124/JBIES-20-00175 (scoping review); PROSPERO CRD 42020168187 (efficacy reviews); https://osf.io/preprints/sportrxiv/y7sk6/ (efficacy review 1); https://osf.io/preprints/sportrxiv/eyxgk/ (efficacy review 2); https://osf.io/preprints/sportrxiv/mx5pv/ (efficacy review 3); PROSPERO CRD42020164641 (mixed-method review).

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) HTA programme and will be published in full in HTA Journal; Vol. 27, No. 24. See the NIHR Journals Library website for further project information.

Parasympathetic Dominance Decreases the Choroidal Blood Flow Velocity Measured Using Laser Speckle Flowgraphy

BACKGROUND

This study aimed to examine the changes to choroidal blood flow velocity using laser speckle flowgraphy (LSFG) in healthy eyes after warm water immersion at 40°C.

METHODS

Data regarding the right eyes of 23 healthy volunteers were included. The mean blur rate (MBR) of the macula, which represents the choroidal blood flow velocity, was evaluated using LSFG. Intraocular pressure (IOP), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), ocular perfusion pressure (OPP), and MBR were assessed at baseline, immediately after immersion (0 minutes), and 10, 20, and 30 minutes later.

RESULTS

At 0 minutes, SBP, DBP, MBP, and OPP values were lower than those at baseline. The MBR significantly declined immediately after immersion to -6.0 ± 5.2%. However, there were no changes in these parameters after 10, 20, or 30 minutes. A significant positive correlation was observed between the MBR, SBP, DBP, MBP, and OPP values. In healthy individuals, the dominant parasympathetic activity induced by warm stimulation reduced the choroidal hemodynamic rate in the macula and decreased systemic circulatory dynamics, which normalized after 10 minutes.

CONCLUSIONS

These findings suggest that the dominant parasympathetic activity induced by warm water immersion at 40°C may lead to a reduction in the systemic circulation rate and choroidal blood flow rate in the macula. These findings may help prevent and treat various retinal choroidal diseases, in which sympathetic hyperactivity is involved in the pathogenesis of the disease.

The effects of immersion in 42℃ radon, natrium, calcium, bicarbonate content thermal-mineral water on chronic low back pain. Controlled, follow-up study

In our minimized follow-up trial with 137 participants with chronic low back pain, one group of participants received regular outpatient care, and the other group received balneotherapy by immersion in 42℃ thermal-mineral water in addition to regular outpatient care on 15 occasions for 3 weeks. Pain on movement and at rest on the 0-100 mm visual analogue scale (VAS), Oswestry index, the number of participants evaluating the symptoms clinically acceptable (Patient Acceptable Symptom State, PASS) and the EuroQol-5D-5L (EQ-5D-5L) quality of life questionnaire were assessed at basal time (at week 0) and after balneotherapy (at weeks 3 and 12). The VAS pain scores, the Oswestry index, the EQ-5D-5L index and the EQ-VAS significantly improved in the balneotherapy group after treatment at week 3 (p < 0.001) and week 12 (p < 0.001) compared to baseline, with a significant between group difference at week 3 (p < 0.001) and week 12 (p < 0.001). The pain VAS score on movement was 66.82 ± 11.48, 26.69 ± 21.49, and 20.09 ± 23.29 in the balneotherapy group, and 63.67 ± 14.77, 67.35 ± 15.44, and 70.23 ± 18.26 in the control group at the consecutive visits. The PASS increased in both groups at week 3 and week 12 compared to the baseline, with a significant between-group difference at week 3 and week 12 for the balneotherapy group. Our results suggest the therapeutic efficacy of immersion in 42℃ thermal mineral water on chronic low back pain.ClinicalTrials.gov Identifier: NCT05342051.

Effects of alternating heat and cold stimulation at different cooling rates using a wearable thermo device on shoulder muscle stiffness: a cross-over study

Background

A small, wearable thermo device that uses Peltier elements for programmed heat and cold stimulation has been developed recently and is expected to be applied in conventional contrast bath therapy. This study was aimed to examine improvements in trapezius muscle hardness and subjective symptoms resulting from alternating heat and cold stimulation, with different rates of cooling.

Methods

This cross-over study included four conditions. Twenty healthy young male individuals (age, 22.3 ± 4.5 years) participated in this study. These four interventions targeted the unilateral trapezius muscle of the dominant arm after a 15-min typing task. Specifically, heat and cold stimulations were applied at different ratios (the heating/cooling rate of 3:1, 3:2, and 3:3) or not applied. Each intervention was separated by at least one week. Skin temperature at the stimulation area was recorded using a data logger. Outcome measures included muscle hardness (measured using a portable tester) and subjective symptoms (muscle stiffness and fatigue). Each item was assessed at three time points: baseline, after typing, and after the intervention.

Results

Two-way analysis of variance with repeated measures found an interaction effect for muscle hardness between four conditions (3:1, 3:2, 3:3, and no) and three time points (p < 0.05). Only in the 3:1 condition were the post-intervention values lower than those after typing (p < 0.01). There was also an interaction effect for subjective muscle stiffness (p < 0.05); the values after the intervention in the 3:1 condition were lower than those after intervention in the no stimulation condition (p < 0.01). There was no significant relationship between changes in muscle hardness and changes in subjective symptoms in the 3:1 condition.

Conclusions

Our results demonstrate that alternating heat and cold stimulations with a different cooling rate could affect the degree of improvement in muscle hardness and subjective symptoms. In particular, the 3:1 condition has the possibility to improved muscle hardness within the condition and subjective muscle stiffness between conditions.

Trial registration

UMIN000040620. Registered 1 June 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046359

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05623-z.