The hemodynamic changes during cupping therapy monitored by using an optical sensor embedded cup

Application of near-infrared spectroscopy to assess the effect of the cupping size on the spatial hemodynamic response from the area inside and outside the cup of the biceps

Cupping therapy is a popular intervention for improving muscle recovery after exercise although clinical evidence is weak. Previous studies demonstrated that cupping therapy may improve microcirculation of the soft tissue to accelerate tissue healing. However, it is unclear whether the cupping size could affect the spatial hemodynamic response of the treated muscle. The objective of this study was to use 8-channel near-infrared spectroscopy to assess this clinical question by assessing the effect of 3 cupping sizes (35, 40, and 45 mm in inner diameter of the circular cup) under -300 mmHg for 5 min on the muscle hemodynamic response from the area inside and outside the cup, including oxyhemoglobin and deoxy-hemoglobin in 18 healthy adults. Two-way factorial design was used to assess the interaction between the cupping size (35, 40, and 45 mm) and the location (inside and outside the cup) and the main effects of the cupping size and the location. The two-way repeated measures ANOVA demonstrated an interaction between the cupping size and the location in deoxy-hemoglobin (P = 0.039) but no interaction in oxyhemoglobin (P = 0.100), and a main effect of the cup size (P = 0.001) and location (P = 0.023) factors in oxyhemoglobin. For the cupping size factor, the 45-mm cup resulted in a significant increase in oxyhemoglobin (5.738±0.760 μM) compared to the 40-mm (2.095±0.312 μM, P<0.001) and 35-mm (3.134±0.515 μM, P<0.01) cup. Our findings demonstrate that the cupping size and location factors affect the muscle hemodynamic response, and the use of multi-channel near-infrared spectroscopy may help understand benefits of cupping therapy on managing musculoskeletal impairment.

Using multi-channel near-infrared spectroscopy to assess the effect of cupping therapy on the spatial hemodynamic response of the biceps muscle: A preliminary study

BACKGROUND

The local hemodynamic response after cupping therapy has been considered as a contributing factor for improving muscle tissue health; however, the effects of cupping pressure and duration on the spatial hemodynamic response have not been investigated.

OBJECTIVE

The objective of this study was to investigate the hemodynamic response inside and outside the cupping cup under various pressures and durations of cupping therapy.

METHODS

A 3-way factorial design with repeated measures was used to investigate the main and interaction effects of the location (areas inside and outside the cup), pressure (-225 and -300 mmHg) and duration (5 and 10 min) on the hemodynamic response of the biceps muscle. A functional near-infrared spectroscopy was used to assess hemodynamic changes in 18 participants.

RESULTS

A significant three-way interaction of the location, pressure, and duration factors was observed in oxyhemoglobin (p= 0.023), deoxy-hemoglobin (p= 0.013), and blood volume (p= 0.013). A significant increase was observed in oxyhemoglobin, blood volume, and oxygenation compared to pre-cupping (p< 0.05) in the area outside the cup.

CONCLUSION

Our findings indicate that an appropriate combination of cupping pressure and duration can effectively affect the spatial hemodynamic response of the biceps.

A randomized controlled trial investigating the impact of a single flash cupping session on patients with chronic lower back pain using multichannel surface electromyographic assessment

BACKGROUND

Chronic lower back pain (CLBP) is one of the most common disorders worldwide. Flash cupping has the ability to relieve CLBP; nevertheless, its impact on CLBP and the likely mechanism of action have not been studied.

OBJECTIVE

The goal of this study was to assess the impact of a single, brief cupping session on CLBP and low back muscle activity using multichannel surface electromyography (sEMG).

METHODS

In this randomized controlled trial, 24 patients with CLBP were enrolled and randomly assigned to the control group (treated by acupuncture) and cupping group (treated by acupuncture and flash cupping). Acupuncture was applied on the shen shu (BL23), dachang shu (BL25), and wei zhong (BL40) acupoints in both the groups. A brief cupping treatment was applied to the shen shu (BL23), qihai shu (BL24), dachang shu (BL25), guanyuan shu (BL26), and xiaochang shu (BL27) acupoints on both sides of the lower back in the cupping group. The numeric rating scale (NRS) was used to assess therapy efficacy for lower back pain (LBP) before and after treatment. Surface EMG data collected during symmetrical trunk flexion-extension movements were utilized to measure lower back muscle activity and the effectiveness of LBP therapy.

RESULTS

There was no statistically significant difference (P= 0.63) in pain intensity between the two groups before and after treatment. There was a statistically significant difference (P= 0.04) between the control group and the cupping group in the sEMG topographic map parameter CoGx-To-Midline.

CONCLUSION

This study established a connection between the action mechanism of flash cupping and enhanced horizontal synchronization of lower back muscular activity.

Efficacy of cupping therapy on pain outcomes: an evidence-mapping study

Objective

Cupping therapy is an ancient technique of healing used to treat a variety of ailments. An evidence-mapping study was conducted to summarize the existing evidence of cupping therapy for pain-related outcomes and indicate the effect and the quality of evidence to provide a comprehensive view of what is known.

Methods

PubMed, Cochrane Library, Embase, and Web of Science were searched to collect the meta-analyses investigating the association between cupping therapy and pain-related outcomes. The methodological quality was assessed by using the AMSTAR 2 tool. Significant outcomes (p < 0.05) were assessed using the GRADE system. The summary of evidence is presented by bubble plots and human evidence mapping.

Results

Fourteen meta-analyses covering five distinct pain-related conditions were identified and assessed for methodological quality using the AMSTAR 2, which categorized the quality as critically low (36%), low (50.0%), moderate (7%), and high (7%). In accordance with the GRADE system, no high-quality evidence was found that demonstrates the efficacy of cupping therapy for pain-related outcomes. Specifically, for neck pain, there were two moderate-quality, four low-quality, and two very low-quality evidence, while only one very low-quality evidence supports its efficacy in treating herpes zoster and one low-quality evidence for chronic back pain. Additionally, for low back pain, there were two moderate-quality, one low-quality, and four very low-quality evidence, and for knee osteoarthritis, three moderate-quality evidence suggest that cupping therapy may alleviate pain score.

Conclusion

The available evidence of very low-to-moderate quality suggests that cupping therapy is effective in managing chronic pain, knee osteoarthritis, low back pain, neck pain, chronic back pain, and herpes zoster. Moreover, it represents a promising, safe, and effective non-pharmacological therapy that warrants wider application and promotion.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021255879, identifier: CRD42021255879.

Using near-infrared spectroscopy to investigate the effects of pressures and durations of cupping therapy on muscle blood volume and oxygenation

Cupping therapy has been widely used to manage musculoskeletal impairment. However, the effects of pressure and duration of cupping therapy on the hemodynamic activity of the muscle have not been investigated. A 2 × 2 repeated measures factorial design was used to examine the main effect and interaction of pressure (-225 and -300 mmHg) and duration (5 and 10 min) on biceps muscle blood flow using near-infrared spectroscopy in 18 participants. The results showed that a significant interaction is between pressure and duration on deoxy-hemoglobin (p = 0.045). A significant main effect of pressure is on oxyhemoglobin (p = 0.005) and a significant main effect of duration is on oxyhemoglobin (p = 0.005). Cupping therapy at -300 mmHg for 10 min results in a higher oxyhemoglobin (6.75 ± 2.08 μM) and deoxy-hemoglobin (1.71 ± 0.78 μM) compared to other three combinations. Our study provides first evidence that the pressure and duration factors of cupping therapy can significantly affect muscle blood volume and oxygenation.

Acute Effects of Dermal Suction on Passive Muscle and Joint Stiffness

The aim of the present study was to examine the acute effects of dermal suction on the passive mechanical properties of specific muscles and joints. Dermal suction was applied to the calves of 24 subjects. Passive plantar flexion torque was measured with the right knee fully extended and the right ankle positioned at 20°, 10°, 0°, and −10° angles, where 0° represents the ankle neutral position, and positive values correspond to the plantar flexion angle. The shear wave velocity (SWV) (m/s) of the medial gastrocnemius was measured in the same position using ultrasound shear wave elastography. The relationship between the joint angle and passive torque at each 10° angle was defined as passive joint stiffness (Nm/°). Passive muscle and joint stiffness were measured immediately before and after the dermal suction protocol. When the ankle joint was positioned at 20° (r = 0.53, P = 0.006), 10° (r = 0.43, P = 0.030), and −10° (r = 0.60, P = 0.001), the SWV was significantly higher after dermal suction than that before dermal suction. Regarding joint stiffness, we found no significant difference between the pre- and post-dermal suction values (partial η² = 0.093, P > 0.05). These findings suggest that dermal suction increases passive muscle stiffness and has a limited impact on passive joint stiffness.

An Experimental Study on the Pressure Range of Fire Cupping Method

Background: Standardized procedures for the clinical application of fire cupping methods have not been established. In particular, the pressure parameters have not been fully characterized and described. Therefore, using various materials, this study investigated the pressure range exerted during fire cupping therapy. Methods: In this study, 3 differently sized (small, medium, large) glass and bamboo cups were used in the cotton ball fire cupping procedure to measure the pressure inside the cup applied to a human skin model. The pressure in each cup was measured 15 times for a total of 90 measurements. Results: A small bamboo cup had the minimum overall pressure (-305.4 mmHg), whereas the large glass cup exerted the maximum pressure (-401.3 mmHg), followed by the medium glass cup, large bamboo cup, small glass cup, and medium bamboo cup. The average pressure exerted by the cotton ball method for all cups ranged from -348.715 mmHg to -358.694 mmHg (95% confidence interval). Overall, the glass cups had a greater pressure than the bamboo cups in all groups (p < 0.001). Among the glass cups used, the larger the size of the cup, the higher the average pressure detected (-381.947 mmHg to -391.973 mmHg; p < 0.05). Conclusion: Large glass cups which are widely used in clinical practice, when used in the fire cupping method exerted pressure ranging from -381.947 mmHg to -391.973 mmHg (95% CI).

Attentional Bias Toward Cupping Therapy Marks: An Eye-Tracking Study

Objective

Despite the many medical benefits, cupping therapy can be difficult for some patients due to unpleasant marks on the skin. As patients are afraid of the potential painful sensation from cupping therapy, the skin reactions might produce vigilance for treatment as pain-related information. We investigated whether individuals show negative emotions and attentional bias toward pain-related residual marks from cupping therapy on the body using an eye-tracking method.

Methods

Fifty pain-free volunteers were presented with four different kinds of visual stimulation, such as the back or face region and with or without cupping marks on the skin. A cupping and a control image were presented on one screen with one image on the left side of the screen and the other on the right (locations of the images were counterbalanced across participants). The eye movements of the participants were measured while they viewed the pictures. They completed the Empathy Quotient questionnaire before the experiment and evaluated the unpleasantness level to each image during the task.

Results

Images of the back and face with cupping marks were rated significantly more unpleasant and showed a significant attentional bias (significantly longer percentage fixation time) than the control images (attentional bias score: Back + cupping: 48.1 ± 2.8%; Back: -0.7 ± 3.4%; Face + cupping: 34.5 ± 2.5%; Face: -2.2 ± 2.9%). Individuals with greater empathy exhibited significantly higher unpleasantness (r = 0.323, p < 0.05) and less attentional bias (r = -0.279, p < 0.05) to the images with cupping marks.

Conclusion

The skin reactions caused by cupping therapy evoked negative emotional responses as well as attentional bias to the reaction sites. Our findings suggest that the emotional and attentional responses to cupping therapy might reflect potential reluctance to this therapy.

Photoacoustic imaging of microenvironmental changes in facial cupping therapy

As a traditional medicine practice, cupping therapy has been widely used to relieve symptoms like fatigue, tension, and muscle pain. During the therapy, negative pressure is applied to the skin for a while with an intention to enhance blood circulation or induce micro-bleeding. The therapeutic effect, however, is not clear due to the lack of direct quantification. Aiming at a quantitative assessment of the treatment effect, we explore optical-resolution photoacoustic microscopy (OR-PAM) in monitoring the structural and functional changes after cupping. We find that, after 5-minutes of ∼ 20 kPa negative pressure cupping, more capillaries appear in the focus, and micro-blooding is observed from the capillaries. We quantify the images and find the blood vessel density is increased by 64%, and the total hemoglobin concentration in both the veins and the arteries exhibits 62% and 40% elevation, respectively. Oxygen saturation in the vein and artery decreased by 17% and 3% right after cupping, respectively. After two hours of recovery, the three blood-related parameters return to their original levels, indicating that the effects in the tissue last only a short period after cupping at the given pressure and time duration. Note that no significant cupping marks are induced with the treatment parameters in this study. This work proposes OR-PAM to quantitatively monitor and evaluate the effect of cupping therapy from the perspective of imaging. The method is also useful for accurate control of the therapeutic outcome.