Acute effects of cold spray application on mechanical properties of the rectus femoris muscle in athletes.

INTRODUCTION: Cold spray is a form of cryotherapy used in acute injuries at sports medicine. In the current study, we aimed to investigate the acute effect of cold spray application as a treatment strategy for acute sports injuries on the mechanical properties of the rectus femoris muscle in athletes. METHODS: The study included 23 volunteer active male athletes between the ages of 18-23 with a subepidermal fold thickness of the rectus femoris muscle between 5 mm and 15 mm. Skin temperature (thermal camera) and mechanical property evaluations of the muscle (Myoton Pro) were measured before, immediately after, and in 2 min, 5 min, 10 min and 15 min intervals following cold spray application. RESULTS: The skin temperature value of the athletes were significantly lower even in the 15-min interval following application (p < 0.001). Muscle tone increased significantly after the application and in the second minute compared to the pre-application (p < 0.001). Muscle stiffness increased significantly only after the second and fifth minutes compared to the pre-application (p < 0.001). Muscle decrement showed an increase in all time-points compared to the pre-application (p < 0.05). CONCLUSION: In athletes, the rectus femoris muscle has been observed to become harder and less elastic following cooling with cold spray. These changes did not improve completely following the 5 min. The muscle regained its mechanical properties at the earliest approximately 10 min after the cold spray application.

Effects of moderate aerobic exercise, low-level laser therapy, or their combination on muscles pathology, oxidative stress and irisin levels in the mdx mouse model of Duchenne muscular dystrophy.

This study aimed to investigate how the combined use of low-level laser therapy (LLLT) and exercise, to reduce the possible side effects and/or increase the benefits of exercise, would affect oxidative stress, utrophin, irisin peptide, and skeletal, diaphragmatic, and cardiac muscle pathologies. In our study, 20 mdx mice were divided into four groups. Groups; sedentary and placebo LLLT (SC), sedentary and LLLT (SL), 30-min swimming exercise (Ex), and 30-min swimming exercise and LLLT (ExL). After 8 weeks of swimming exercise, muscle tests, biochemically; oxidative stress index (OSI), utrophin and irisin levels were measured. Skeletal, diaphragmatic and cardiac muscle histopathological scores, skeletal and cardiac muscle myocyte diameters were determined under the light and electron microscope. While only irisin levels were increased in group SL compared to SC, it was determined that OSI, heart muscle histopathological scores decreased and irisin levels increased in both exercise groups (p < 0.05). In addition, in the ExL group, an increase in rotarod and utrophin levels, and a decrease in muscle and diaphragm muscle histopathological scores were observed (p < 0.05). It was determined that the application of swimming exercise in the mdx mouse model increased the irisin level in the skeletal muscle, while reducing the OSI, degeneration in the heart muscle, inflammation and cardiopathy. When LLLT was applied in addition to exercise, muscle strength, skeletal muscle utrophin levels increased, and skeletal and diaphragmatic muscle degeneration and inflammation decreased. In addition, it was determined that only LLLT application increased the level of skeletal muscle irisin.

Comparison of the Immediate Effect of Petrissage Massage and Manual Lymph Drainage Following Exercise on Biomechanical and Viscoelastic Properties of the Rectus Femoris Muscle in Women.

CONTEXT: Fast and adequate recovery after exercise and activity is important for increasing performance and preventing injuries. Inadequate recovery usually causes changes in the biomechanical and viscoelastic properties of the muscle. OBJECTIVE: To compare the immediate effect of petrissage massage (PM) and manual lymph drainage (MLD) following submaximal exercise on the biomechanical and viscoelastic properties of the rectus femoris muscle in healthy women. DESIGN: Cross-sectional, repeated-measures. SETTING: Marmara University. PARTICIPANTS: 18 healthy female students. INTERVENTION(S): Following the submaximal quadriceps strengthening exercise performed in 3 sets of 8 repetitions with intensity of 75% of 1 maximum repetition, participants' right leg received a 5-minute PM (PM group) and the contralateral leg received a 5-minute MLD application (MLD group). MAIN OUTCOME MEASURES: Skin temperature was measured using P45 thermographic thermal camera (Flir System; ThermaCAM, Danderyd, Sweden), and muscle tone, biomechanical, and viscoelastic features were measured with a myometer (Myoton AS, Tallinn, Estonia) at baseline, immediately postexercise, post-PM/MLD application, and 10 minutes postexercise. RESULTS: In the PM group, the tonus (P = .002) and stiffness (P < .001) values measured after the massage and at the end of the 10-minute resting period were found to be statistically different than those measured right after the exercise (P < .05). Relaxation time and creep values at all measurement times were significantly different (P < .05). In the MLD group, it was observed the tonus (P < .001), stiffness (P = .025), and relaxation time (P < .01) values decreased significantly after the MLD compared with the values measured after the exercise; however, the creep value was found to be significantly different in all measurements (P < .05). CONCLUSION: PM and MLD reduce passive tissue stiffness and improve the extent of muscle extensibility over time against the muscle tensile strength. PM and MLD are therapeutic methods that can be used to support tissue recovery after exercise and prevent injuries.

Acute Effects of Cold Pack for Different Periods on the Biomechanical Properties of the Rectus Femoris Muscle.

CONTEXT: Cold packs are silica gel packs that are commonly used in clinics. However, the packs are applied for various amounts of time, and the relationship between these times and temperature changes isn't fully understood. OBJECTIVES: The study intended to investigate the acute effects of cold-pack application for different periods of time on the biomechanical properties of the rectus femoris muscle. DESIGN: The study was randomized, controlled trial. SETTING: The study took place at Acibadem Mehmet Ali Aydinlar University in Istanbul, Turkey. PARTICIPANTS: Participants were 60 healthy volunteers from the community, aged 18 to 23 years. INTERVENTIONS: Participants were divided into four groups with n = 15 in each group. The cold packs were applied on the dominant rectus femoris muscle: (1) for 10 minutes in Group 1, (2) for 12 minutes in Group 2, (3) for 15 minutes in Group 3, and (4) for 20 minutes in Group 4. OUTCOME MEASURES: The outcome measures were the skin temperature, determined using a thermal camera, and biomechanical properties-tone and stiffness and muscle decrement-using a device that delivers a short mechanical impulse to the tissue. Outcomes were measured at baseline before the cold application, immediately post intervention after the cold application, and at 5, 10, 15, 20, and 30 minutes post intervention. RESULTS: The mean skin temperatures were significantly lower in all groups compared to those before cold application (P < .05), and no significant differences existed between any of the groups (P > .05). Post intervention, while Groups 1 and 2 showed an increase in muscle tone and stiffness and a decrease in elasticity (P < .05), they began to approach their baseline state by the fifth and fifteenth minutes, respectively (P > .05). In Groups 3 and 4, the muscle stiffness increased at all time points (P < .05). CONCLUSIONS: The study showed that the rectus femoris muscle of healthy people becomes stiffer and less elastic as a result of cooling with cold packs that were applied for different time periods. The amount of cold-pack time that minimized the biomechanical corruption of the muscle and provides cooling was 10 minutes. Careful warming up is recommended before and after intense athletic performance, and caution in cooling the skeletal muscle should be exercised.

Treatment with milk thistle extract (Silybum marianum), ursodeoxycholic acid, or their combination attenuates cholestatic liver injury in rats: Role of the hepatic stem cells.

BACKGROUND/AIMS: Cholestasis, which results in hepatic cell death, fibrosis, cirrhosis, and eventually liver failure, is associated with oxidative stress. The aim of this study was to evaluate the effects of milk thistle (MT, Silybum marianum) and ursodeoxycholic acid (UDCA) or their combination on the activation of hepatic stem cells and on the severity of cholestasis liver injury in rats. MATERIALS AND METHODS: Under anesthesia, bile ducts of female Sprague Dawley rats were ligated (BDL) or had sham operation. BDL rats were administered saline, UDCA (15 mg/kg/d), MT (600 mg/kg/d), or UDCA+MT by gavage for 10 days. On the 11th day, rats were sacrificed and blood and liver samples were obtained. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA) levels, and myeloperoxidase (MPO) activity were measured. Hepatic injury, a-smooth muscle actin expression, and stem cell markers c-kit, c-Myc, Oct3/4, and SSEA-1 were histologically determined. RESULTS: Histological scores, serum ALT, and hepatic MDA levels were higher in BDL group than in the sham rats, while all treatments significantly reduced these levels. The reduction in ALT was significantly greater in UCDA+MT-treated group than in other treatment groups. c-Kit, c-Myc, Oct3/4, and SSEA-1 were increased in saline-treated BDL group with respect to sham-operated control group, and these markers were significantly reduced in all treatment groups. CONCLUSION: In addition to a modulatory effect on the stem cell-induced regenerative response of the liver, UDCA, MT, and their combination demonstrated similar anti-inflammatory and antiproliferative effects on cholestasis-induced hepatic injury.