Caroline Haas

Massage timing affects postexercise muscle recovery and inflammation in a rabbit model.

PURPOSE This study compared the effect of immediate versus delayed massage-like compressive loading (MLL) on peak isometric torque recovery and inflammatory cell infiltration after eccentric exercise (EEX). METHODS Eighteen skeletally mature New Zealand White rabbits were instrumented with peroneal nerve cuffs for the stimulation of hindlimb tibialis anterior muscles. After a bout of EEX, rabbits were randomly assigned to an MLL protocol (0.5 Hz, 10 N, 15 min) that started immediately post-EEX, 48 h post-EXX, or no-MLL control and performed for four consecutive days. A torque-angle (T-Θ) relationship was obtained for 21 joint angles pre- and post-EEX and after four consecutive days of MLL or no-MLL. Muscle wet weights and immunohistochemical sections were obtained after final treatments. RESULTS EEX produced an average 51% ± 13% decrease in peak isometric torque output. The greatest peak torque recovery occurred with the immediate application of MLL. There were differences in torque recovery between immediate and delayed MLL (P = 0.0012), immediate MLL and control (P < 0.0001), and delayed MLL and control (P = 0.025). Immunohistochemical analysis showed 39.3% and 366.0% differences in the number of RPN3/57 and CD11b-positive cells between immediate (P = 0.71) and delayed MLL (P = 0.12). The area under the T-Θ curve showed a difference for immediate (P < 0.0001) and delayed (P = 0.0051) MLL as compared with control. Exercise produced an average 10° ± 0.2° rightward shift from preexercise peak isometric torque angle. Control, immediate MLL, and delayed MLL produced an average leftward angular shift from the postexercise angle (P = 0.28, P = 0.03, and P = 0.47, respectively). CONCLUSION Post-EEX, immediate MLL was more beneficial than delayed MLL in restoring muscle function and in modulating inflammatory cell infiltration. These findings invite similar human studies to make definitive conclusions on optimal timing of massage-based therapies.

Dose-dependency of massage-like compressive loading on recovery of active muscle properties following eccentric exercise: rabbit study with clinical relevance

Background Optimal strategies for massage and its use in athletes have not been conclusively demonstrated. Purpose/study design Effects of varying duration, frequency and magnitude of massage-like compressive loading (MLL) on recovery of skeletal muscle active properties (torque angle (T-Θ) relationship) following exercise-induced muscle injury were studied. Methods Twenty-four New Zealand White rabbits were surgically instrumented with bilateral peroneal nerve cuffs for stimulation of hindlimb tibialis anterior muscles. Following a bout of eccentric exercise (EEX), rabbits were randomly assigned to a MLL protocol of 0.25 or 0.5 Hz at 5 or 10 N for 15 or 30 min. T-Θ was obtained for 21 tibiotarsal joint angles pre- and post-EEX and post 4 consecutive days of MLL. Muscle wet weight and H&E sections were obtained following final treatments. Results EEX produced an average 61.8%±2.1 decrease in peak isometric torque output. Differences in torque recovery were found between magnitudes (5 and 10 N; p=0.004, n=12) and frequencies (0.25 and 0.5 Hz; p=0.012, n=12), but no difference for durations (15 and 30 min) with the 0.5 Hz, 10 N, 15 min protocol showing greatest recovery 4 days post-EEX. MLL muscle (n=12) wet weight was 3.22±0.18 g, while no MLL tissue (n=9) weighed 3.74±0.22 g (p=0.029). Histological analysis showed a difference in torn fibres between low-parameter and high-parameter MLL (6.5±1.04 vs 0.5±0.29 per 0.59 mm2, p=0.005). Conclusions Results showed a dose-response effect for magnitude and frequency of MLL on recovery of active muscle properties following EEX. Future studies will investigate underlying biological mechanisms for this enhanced recovery of muscle function.

In vivo passive mechanical properties of skeletal muscle improve with massage-like loading following eccentric exercise.

A quasi-linear viscoelasticity (QLV) model was used to study passive time-dependent responses of skeletal muscle to repeated massage-like compressive loading (MLL) following damaging eccentric exercise. Six skeletally mature rabbits were surgically instrumented with bilateral peroneal nerve cuffs for stimulation of the hindlimb tibialis anterior (TA) muscles. Following the eccentric exercise, rabbits were randomly assigned to a four-day MLL protocol mimicking deep effleurage (0.5 Hz, 10 N for 15 min or for 30 min). The contralateral hindlimb served as the exercised, no-MLL control for both MLL conditions. Viscoelastic properties of the muscle pre-exercise, post-exercise on Day 1, and pre- and post-MLL Day 1 through Day 4 were determined with ramp-and-hold tests. The instantaneous elastic response (AG(0)) increased following exercise (p<0.05) and decreased due to both the 15 min and 30 min four-day MLL protocols (p<0.05). Post-four days of MLL the normalized AG(0) decreased from post-exercise (Day 1, 248.5%) to the post-MLL (Day 4, 98.5%) (p<0.05), compared to the no-MLL group (Day 4, 222.0%) (p<0.05). Exercise and four-day MLL showed no acute or cumulative effects on the fast and slow relaxation coefficients (p>0.05). This is the first experimental evidence of the effect of both acute (daily) and cumulative changes in viscoelastic properties of intensely exercised muscle due to ex vivo MLL. It provides a starting point for correlating passive muscle properties with mechanical effects of manual therapies, and may shed light on design and optimization of massage protocols.

A Mechatronic System for Quantitative Application and Assessment of Massage-Like Actions in Small Animals

Massage therapy has a long history and has been widely believed effective in restoring tissue function, relieving pain and stress, and promoting overall well-being. However, the application of massage-like actions and the efficacy of massage are largely based on anecdotal experiences that are difficult to define and measure. This leads to a somewhat limited evidence-based interface of massage therapy with modern medicine. In this study, we introduce a mechatronic device that delivers highly reproducible massage-like mechanical loads to the hind limbs of small animals (rats and rabbits), where various massage-like actions are quantified by the loading parameters (magnitude, frequency and duration) of the compressive and transverse forces on the subject tissues. The effect of massage is measured by the difference in passive viscoelastic properties of the subject tissues before and after mechanical loading, both obtained by the same device. Results show that this device is useful in identifying the loading parameters that are most conducive to a change in tissue mechanical properties, and can determine the range of loading parameters that result in sustained changes in tissue mechanical properties and function. This device presents the first step in our effort for quantifying the application of massage-like actions used clinically and measurement of their efficacy that can readily be combined with various quantitative measures (e.g., active mechanical properties and physiological assays) for determining the therapeutic and mechanistic effects of massage therapies.

Effects of immediate vs. delayed massage-like loading on skeletal muscle viscoelastic properties following eccentric exercise

BACKGROUND This study compared immediate versus delayed massage-like compressive loading on skeletal muscle viscoelastic properties following eccentric exercise. METHODS Eighteen rabbits were surgically instrumented with peroneal nerve cuffs for stimulation of the tibialis anterior muscle. Rabbits were randomly assigned to a massage loading protocol applied immediately post exercise (n=6), commencing 48h post exercise (n=6), or exercised no-massage control (n=6). Viscoelastic properties were evaluated in vivo by performing a stress-relaxation test pre- and post-exercise and daily pre- and post-massage for four consecutive days of massage loading. A quasi-linear viscoelastic approach modeled the instantaneous elastic response (AG0), fast (g1(p)) and slow (g2(p)) relaxation coefficients, and the corresponding relaxation time constants τ1 and τ2. FINDINGS Exercise increased AG0 in all groups (P<0.05). After adjusting for the three multiple comparisons, recovery of AG0 was not significant in the immediate (P=0.021) or delayed (P=0.048) group compared to the control group following four days of massage. However, within-day (pre- to post-massage) analysis revealed a decrease in AG0 in both massage groups. Following exercise, g1(p) increased and g2(p) and τ1 decreased for all groups (P<0.05). Exercise had no effect on τ2 (P>0.05). After four days of massage, there was no significant recovery of the relaxation parameters for either massage loading group compared to the control group. INTERPRETATION Our findings suggest that massage loading following eccentric exercise has a greater effect on reducing muscle stiffness, estimated by AG0, within-day rather than affecting recovery over multiple days. Massage loading also has little effect on the relaxation response.

P01.42. Dose-dependent effects of massage-like loading in an animal model following eccentric exercise

Methods Twenty-four New Zealand white rabbits were surgically instrumented and underwent a bout of damaging eccentric exercise to the tibialis anterior muscle. Rabbits were randomly assigned to a protocol with massage frequency of 0.25 or 0.50Hz at a compressive force of 5 or 10N for 15 or 30 minutes. The contralateral limb served as the exercised, non-massaged control. A torque-angle relationship was obtained for 21 tibiotarsal joint angles, preand post-exercise, and post four consecutive days of massage (applied by customized device). Peak isometric torque was the primary outcome variable. Muscle wet weight and histological analysis were also performed at the end of the protocol.