Previous studies have shown significant improvement in muscle soreness and muscle function loss after 300-s foam rolling intervention two days after intense exercise. However, this duration is assumed to be too long, so investigating the effect of short-term duration foam rolling intervention on an eccentrically-damaged muscle is needed. This study aimed to eccentrically induce muscle damage in the leg extensors, and to detect the acute effect of 90-s foam rolling on muscle soreness and muscle function of the quadriceps muscle. We enrolled 17 healthy and nonathlete male volunteers. They performed a bout of eccentric exercise of the knee extensors with the dominant leg and received 90-s foam rolling intervention of the quadriceps two days after the eccentric exercise. The dependent variables were measured before the eccentric exercise (baseline), and before (preintervention) and after foam rolling intervention (postintervention), two days after the eccentric exercise. The results show that the preintervention muscle soreness and muscle strength values were significantly increased, compared with the baseline values, whereas the postintervention values were significantly decreased, compared with the preintervention values. Furthermore, 90-s of foam rolling intervention could improve muscle soreness and muscle function loss.

The Acute Effect of Foam Rolling on Eccentrically-Induced Muscle Damage

In sports and clinical settings, roller massage (RM) interventions are used to acutely increase range of motion (ROM); however, the underlying mechanisms are unclear. Apart from changes in soft tissue properties (i.e., reduced passive stiffness), neurophysiological alterations such as decreased spinal excitability have been described. However, to date, no study has investigated both jointly. The purpose of this trial was to examine RM's effects on neurophysiological markers and passive tissue properties of the plantar flexors in the treated (ROLL) and non-treated (NO-ROLL) leg. Fifteen healthy individuals (23 ± 3 years, eight females) performed three unilateral 60-s bouts of calf RM. This procedure was repeated four times on separate days to allow independent assessments of the following outcomes without reciprocal interactions: dorsiflexion ROM, passive torque during passive dorsiflexion, shear elastic modulus of the medial gastrocnemius muscle, and spinal excitability. Following RM, dorsiflexion ROM increased in both ROLL (+19.7%) and NO-ROLL (+13.9%). Similarly, also passive torque at dorsiflexion ROM increased in ROLL (+15.0%) and NO-ROLL (+15.2%). However, there were no significant changes in shear elastic modulus and spinal excitability (p > 0.05). Moreover, significant correlations were observed between the changes in DF ROM and passive torque at DF ROM in both ROLL and NO-ROLL. Changes in ROM after RM appear to be the result of sensory changes (e.g., passive torque at DF ROM), affecting both rolled and non-rolled body regions. Thus, therapists and exercise professionals may consider applying remote treatments if local loading is contraindicated.

Local and Non-local Effects of Foam Rolling on Passive Soft Tissue Properties and Spinal Excitability

A stretching intervention program is performed to maintain and improve range of motion (ROM) in sports and rehabilitation settings. However, there is no consensus on the effects of stretching programs on muscle stiffness, likely due to short stretching durations used in each session. Therefore, a longer stretching exercise session may be required to decrease muscle stiffness in the long-term. Moreover, until now the retention effect (detraining) of such an intervention program is not clear yet. The purpose of this study was to investigate the training (5-week) and detraining effects (5-week) of a high-volume stretching intervention on ankle dorsiflexion ROM and medial gastrocnemius muscle stiffness. Fifteen males participated in this study and the plantarflexors of the dominant limb was evaluated. Static stretching intervention was performed using a stretching board for 1,800 seconds at 2 days per week for 5-week. Dorsiflexion ROM was assessed, and muscle stiffness was calculated from passive torque and muscle elongation during passive dorsiflexion test. The results showed significant changes in dorsiflexion ROM and muscle stiffness after the stretching intervention program, but the values returned to baseline after the detraining period. Our results indicate that high-volume stretching intervention (3,600 seconds per week) may be beneficial for dorsiflexion ROM and muscle stiffness, but the training effects are dismissed after a detraining period with the same duration of the intervention.

/pdf/training-and-detraining-effects-following-a-static-4bn4810h6g.pdf

Training and Detraining Effects Following a Static Stretching Program on Medial Gastrocnemius Passive Properties.

Self-massage using foam rollers, sticks, or balls has become a popular technique to enhance joint range of motion (ROM). Although increases are reported to be larger in females than males, the mechanisms of this observation are unclear. The present study aimed to investigate the effect of roller massage (RM) on ROM, passive tissue stiffness, and neurophysiological markers as a function of sex. Males (n = 15, 22.8 ± 2.9 yrs.) and females (n = 14, 21.1 ± 0.7 yrs.) performed three 60-second bouts of calf RM. Outcomes assessed pre-, and post-intervention included passive dorsiflexion (DF) ROM, passive tissue stiffness, passive torque, DF angle at the first stretch sensation, shear elastic modulus, and spinal excitability. DF ROM (+35.9 %), passive torque at DF ROM (+46.4 %), DF angle at first stretch sensation (+32.9 %), and pain pressure threshold (+25.2 %) increased in both groups (p<.05) with no differences between males and females (p > 0.05). No changes were observed for passive stiffness, shear elastic modulus, and spinal excitability (p > 0.05). Roller massage may increase ROM independently of sex, which, in the present study, could not be ascribed to alterations in passive stiffness or neurophysiological markers. Future studies may further elucidate the role of sensory alterations as possible factors driving RM-induced changes in flexibility.

Sex Differences in the Mechanical and Neurophysiological Response to Roller Massage of the Plantar Flexors

Effects of stretching intensity on range of motion and muscle stiffness: A narrative review.

This study aimed to investigate the relationship between relative or absolute intensity and changes in range of motion and passive stiffness after static stretching. A total of 65 healthy young adults voluntarily participated in this study and performed static stretching of the plantar flexor-muscle for 120 s. Dorsiflexion range of motion and passive torque during passive dorsiflexion before and after stretching were assessed. We measured the passive torque at a given angle when the minimum angle was recorded before and after stretching. The angle during stretching was defined as the absolute intensity. Dorsiflexion range of motion before stretching was defined as 100%, and the ratio (%) of the angle during stretching was defined as the relative intensity. A significant correlation was found between absolute intensity and change in passive torque at a given angle (r = -0.342), but relative intensity and range of motion (r = 0.444) and passive torque at dorsiflexion range of motion (r = 0.259). A higher absolute intensity of stretching might be effective in changing the passive properties of the muscle-tendon unit. In contrast, a higher relative intensity might be effective in changing the range of motion, which could be contributed by stretch tolerance.

https://www.mdpi.com/2075-4663/8/11/140/pdf

The Relationship between Stretching Intensity and Changes in Passive Properties of Gastrocnemius Muscle-Tendon Unit after Static Stretching.

The application of superficial icing has often been used in rehabilitation and sport settings. Some previous studies have shown that superficial icing or cooling increased range of motion and muscle stiffness. Considering that previous studies have investigated the effects of superficial icing only after 20 or 30 min, the superficial icing duration needed to increase range of motion has remained unclear. Moreover, another study showed that superficial icing increased spinal excitability, which could consequently increase muscle stiffness, although no study has investigated the relationship between change in muscle stiffness and change in spinal excitability after superficial cooling. The aims of this study was to determine the time required to increase range of motion by investigating changes over time during superficial icing and elucidate the mechanism whereby superficial cooling increased muscle stiffness by investigating the changes in muscle temperature and spinal cord excitability. A total of 19 healthy volunteers participated in 2 experiments, the first of which sought to determine time-course changes in medial gastrocnemius muscle stiffness, dorsiflexion range of motion, passive torque at dorsiflexion range of motion during superficial icing and the second of which sought to investigate the time-course changes in spinal cord excitability in the dominant leg. Our results showed that more than 5 min of superficial icing is required to increase range of motion, while the increase in muscle stiffness could be attributed to the decrease in muscle temperature and not change in spinal excitability.

Time course of changes in range of motion, muscle shear elastic modulus, spinal excitability, and muscle temperature during superficial icing

ストレッチングが遅発性筋痛に及ぼす影響の検討 −Hold relax stretchingとmodified PNF stretchingの比較−

Passive torque during static stretching was decreased. This phenomenon occurs due to stress relaxation. However, no studies have investigated the relationship stress relaxation and changes in range of motion (ROM) or muscle–tendon unit stiffness. Moreover, no study calculated the total volume during static stretching as total work and investigated the relationship between total work and ROM changes or muscle–tendon stiffness. This study aimed to investigate the relationship between stress relaxation, total work from measuring passive torque normalized by muscle thickness and ROM, and muscle–tendon stiffness. A total of 63 healthy students voluntarily participated in this study. Static stretching was performed for the plantar flexor muscles at 120 s. Outcomes were assessed on ROM, passive torque at dorsiflexion ROM, and muscle–tendon stiffness. Stress relaxation was defined as the change of torque from the start to end of static stretching. Total work was defined as the sum of the torque from the start to end of static stretching. Stress relaxation was found to be significantly correlated with muscle–tendon stiffness whether normalized by muscle thickness or not (r = 0.603, r  = 0.599). Furthermore, total work was significantly correlated with muscle–tendon stiffness, regardless of normalization (r = − 0.276, r = − 0.327). However, the relationship among stress relaxation, total work and ROM, and passive torque at dorsiflexion ROM was not significant. Stress relaxation and total work are associated with muscle–tendon stiffness changes after stretching, but not associated with ROM changes.

Kazuki Inaba

Papers

The Relationship between Stretching Intensity and Changes in Passive Properties of Gastrocnemius Muscle-Tendon Unit after Static Stretching.

Time course of changes in range of motion, muscle shear elastic modulus, spinal excitability, and muscle temperature during superficial icing

ストレッチングが遅発性筋痛に及ぼす影響の検討 −Hold relax stretchingとmodified PNF stretchingの比較−

Influence of stress relaxation and load during static stretching on the range of motion and muscle–tendon passive stiffness