- M. Eriksson Crommert, L. Lacourpaille, L. J. Heales, K. Tucker, F. Hug, Scand J Med Sci Sports 2015
The mechanisms behind massage are proposed to be biomechanical [e.g., increased range of motion (ROM), decreased muscle stiffness], physiological (e.g., increased blood flow and muscle temperature, reduced spinal reflex excitability), and/or psychological (e.g., increased relaxation, decreased anxiety). However, there is little compelling evidence for efficacy of this treatment modality. Further, a review on the biomechanical effects of massage reports inconsistent results between studies. This inconsistency may be due in part to the various types of massage and the duration of application.
The aims of this study were with using a ultrasound :
- (a) to evaluate the effect of massage on stiffness of the medial gastrocnemius (MG) muscle (a standardized combination of effleurage, petrissage, and deep circular frictions)
- (b) to determine whether this effect (if any) persists over a short period of rest.
A 7-min massage protocol was performed unilaterally on MG in 18 healthy volunteers.
The massage consist on 4 phrases.
- 2 min of effleurage (Effleurage consisted of deep stroking movements over the skin with a smooth continuous motion),
- 2 min of petrissage (Petrissage consisted of compressing the tissues between the fingers of one hand and the thumb of another while lifting the soft tissues off the underlying structures),
- 2 min of deep circular friction (Deep circular friction was applied using the fingertips and thumb to mobilize the superficial structures (e.g., MG) in relation to the deep structures (e.g., soleus, tibialis posterior))
- 1 min of effleurage.
Directly after massage, participants rated pain experienced during the massage.
MG shear elastic modulus of the massaged leg was significantly lower immediately after massage compared with both baseline and following rest. This decrease in muscle shear elastic modulus compared with baseline is considered a “moderate” effect.
There can be several explanations for the observed short-term reduction in muscle stiffness following massage.
- First, there might be a decrease in motoneuron excitability as the result of a greater general sense of relaxation and/or a local reflex inhibition within the massaged limb. However, the participants were instructed to remain “as relaxed as possible” throughout the testing period, and therefore the massaged muscle (and the con- tralateral non-massaged muscle) was likely to be myoelectrically silent and insensitive to a decrease in spinal/ cortical excitability. Consequently, it is unlikely that even a local decrease in motoneuron excitability may explain the observed decrease in muscle stiffness.
- Second, mechanical effects might explain the reduction in stiffness after massage. By applying pressure and stretching to the underlying muscle tissue, it is possible that massage breaks the stable cross-bridges between the actin and myosin filaments that are spontaneously formed when muscles are at rest.
- Third, it is possible that muscle stiffness decreased as a result of increased intramuscular temperature. Indeed, 5 minutes of massage of the vastus lateralis has been shown to increase intramuscular temperature by 2 °C at 1.5 cm depth. As ex vivo studies suggested that muscle shear elastic modulus is dependant on muscle temperature, with a decrease rate of about −2% °C−1. This could account for, at least in part, the reduction in muscle stiffness observed in the present study. Although possible, we postulate that this cannot be the main explanation for the findings in the present study. This is because there was no relationship between the depth of the measurement (i.e., ROI), which influences the rate of increased temperature and the amount of decrease in muscle stiffness.
- Finally, it is likely that neither of the proposed mechanisms (i.e., breaking of resting cross-bridges and increase in intramuscular temperature) work in isolation, but instead their combined effect is responsible for the observed decrease in muscle stiffness at a moderately stretched position.