Microvascular perfusion increases after eccentric exercise of the gastrocnemius

Immediate Effect of Cryo-Compression Therapy on Biomechanical Properties and Perfusion of Forearm Muscles in Mixed Martial Arts Fighters

Mixed martial arts (MMA) fighters use their arms and hands for striking with the fists, grappling, and defensive techniques, which puts a high load on the forearms and hand muscles. New methods are needed to decrease the risk of injury and increase the effectiveness of regeneration. This study aimed to assess the effectiveness of cryo-compression (CC) therapy of different times (3 and 6 min) on forearm muscles in MMA fighters by investigating muscle pain, stiffness, tension, elasticity strength, and perfusion. Twenty professional male MMA fighters aged 26.5 ± 4.5 years, with training experience of 10.3 ± 5.0 years, were enrolled on an experimental within-group study design. The participants underwent CC therapy at a temperature of 3 °C and compression of 75 mmHg for 3 min and, in the second session, for 6 min. The investigated parameters were in the following order: (1) perfusion in non-reference units (PU), (2) muscle tone (T-[Hz]), (3) stiffness (S-[N/m]), (4) elasticity (E-[arb]), (5) pressure pain threshold (PPT-[N/cm]), and (6) maximum isometric force (Fmax [kgf]) at two time points: (1) at rest-2 min before CC therapy (pre) and (2) 2 min after CC therapy (post). There were significant differences between 3 and 6 min of CC therapy for PU and T. Meanwhile, F, E, PPT, and S were significantly different when comparing pre- to post-conditions. These results provide evidence that CC therapy is a stimulus that significantly affects parameters characterizing muscle biomechanical properties, pain threshold, strength, and tissue perfusion.

Contrast-Enhanced Ultrasound Reveals Exercise-Induced Perfusion Deficits in Claudicants

Background

Contrast-Enhanced Ultrasonography (CEUS) is an imaging modality allowing perfusion quantification in targeted regions of interest of the lower extremity that has not been possible with color-flow imaging or with measurement of ankle brachial indices. We developed a protocol to quantify lower extremity muscle perfusion impairment in PAD patients in response to exercise.

Methods and findings

Thirteen patients with Rutherford Class I-III Peripheral Arterial Disease (PAD) and no prior revascularization procedures were recruited from the Baltimore Veterans Affairs Medical Center and compared with eight control patients without PAD. CEUS interrogation of the index limb gastrocnemius muscle was performed using an intravenous bolus of lipid-stabilized microsphere contrast before and after a standardized treadmill protocol. Peak perfusion (PEAK) and time to peak perfusion (TTP) were measured before and after exercise. Between and within group differences were assessed. Control subjects demonstrated a more rapid TTP (p<0.01) and an increase in peak perfusion (PEAK, p=0.02) after exercise, when compared to their baseline measures. Patients with PAD demonstrated TTP and PEAK measures equivalent to controls at baseline (p=0.39, p=0.71, respectively). However, they exhibited no significant exercise-induced changes in perfusion (TTP p=0.49 and PEAK 0.67, respectively compared to baseline). After exercise, normal subjects had significantly shorter TTP (p=0.04) and greater PEAK (p=0.02) than PAD patients.

Conclusion

Consistent with their lack of ischemic symptoms at rest, class I to III claudicant PAD patients showed similar perfusion measures (TTP and PEAK) at rest. PAD patients, however, were unable to increase perfusion in response to exercise, whereas controls increased perfusion significantly. This corresponds with claudication and limited walking capacity observed in PAD. CEUS with bolus injection offers a convenient, objective, quantitative and visual physiologic assessment of perfusion limitation in specific muscle groups of PAD patients. This has the potential for substantial clinical and research utility.

Blood flow after exercise-induced muscle damage

CONTEXT

The most common modality used to address acute inflammation is cryotherapy. Whereas pain decreases with cryotherapy, evidence that changes occur in perfusion of skeletal muscle is limited. We do not know whether ice attenuates the increases in perfusion associated with acute inflammation.

OBJECTIVE

To examine the effects of repeated applications of ice bags on perfusion of the gastrocnemius muscle after an eccentric exercise protocol.

DESIGN

Controlled laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Eighteen healthy participants (3 men, 15 women; age = 22.2 ± 2.2 years, height = 166.0 ± 11.9 cm, mass = 69.4 ± 25.0 kg).

INTERVENTION(S)

To induce eccentric muscle damage, participants performed 100 unilateral heel-lowering exercises off a step to the beat of a metronome. A randomized intervention (cryotherapy, sham, control) was applied to the exercised lower extremity immediately after the protocol and again at 10, 24, and 34 hours after the protocol.

MAIN OUTCOME MEASURE(S)

Baseline perfusion measurements (blood volume, blood flow, and blood flow velocity) were taken using contrast-enhanced ultrasound of the exercised leg. Perfusion was reassessed after the first intervention and 48 hours after the protocol as percentage change scores. Pain was measured with a visual analog scale at baseline and at 10, 24, 34, and 48 hours after the protocol. Separate repeated-measures analyses of variance were used to assess each dependent variable.

RESULTS

We found no interactions among interventions for microvascular perfusion. Blood volume and blood flow, however, increased in all conditions at 48 hours after exercise (P < .001), and blood flow velocity decreased postintervention from baseline (P = .041). We found a time-by-intervention interaction for pain (P = .009). Visual analog scale scores were lower for the cryotherapy group than for the control group at 34 and 48 hours after exercise.

CONCLUSIONS

Whereas eccentric muscle damage resulted in increased blood flow, ice did not decrease muscle perfusion 48 hours after exercise. Therefore, ice does not seem to decrease muscle perfusion when blood flow is elevated, as it would be during inflammation.