title: Central and peripheral responses to static and dynamic stretch of skeletal muscle: mechano- and metaboreflex implications.
abstract: Passive static stretching (SS), circulatory cuff occlusion (CCO), and the combination of both (SS + CCO) have been used to investigate the mechano- and metaboreflex, respectively. However, the effects of dynamic stretching (DS) alone or in combination with CCO (DS + CCO) on the same reflexes have never been explored. The aim of the study was to compare central and peripheral hemodynamic responses to DS, SS, DS + CCO, and SS + CCO. In 10 participants, femoral blood flow (FBF), heart rate (HR), cardiac output (CO), and mean arterial pressure (MAP) were assessed during DS and SS of the quadriceps muscle with and without CCO. Blood lactate concentration [La-] in the lower limb undergoing CCO was also measured. FBF increased significantly in DS and SS by 365 ± 98 and 377 ± 102 ml/min, respectively. Compared with baseline, hyperemia was negligible during DS + CCO and SS + CCO (+11 ± 98 and +5 ± 87 ml/min, respectively). DS generated a significant, sustained increase in HR and CO (∼40s), while SS induced a blunted and delayed cardioacceleration (∼20 s). After CCO, [La-] in the lower limb increased by 135%. Changes in HR and CO during DS + CCO and SS + CCO were similar to DS and SS alone. MAP decreased significantly by ∼5% during DS and SS, did not change in DS + CCO, and increased by 4% in SS + CCO. The present data indicate a reduced mechanoreflex response to SS compared with DS (i.e., different HR and CO changes). SS evoked a hyperemia similar to DS. The similar central hemodynamics recorded during stretching and [La-] accumulation suggest a marginal interaction between mechano- and metaboreflex.
  
  
  
  Different modalities of passive stretching administration (dynamic or static) in combination with circulatory cuff occlusion may reduce or amplify the mechano- and metaboreflex. We showed a reduced mechanoreflex response to static compared with dynamic stretching. The lack of increase in central hemodynamics during the combined mechano- and metaboreflex stimulation implicates marginal interactions between these two pathways.
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy; massimo.venturelli@univr.it.|Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
authors.forename: Massimo
authors.identifier: 0000-0002-2469-8787
authors.initials: M
authors.lastname: Venturelli
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Cè
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Eloisa
authors.initials: E
authors.lastname: Limonta
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Angela Valentina
authors.initials: AV
authors.lastname: Bisconti
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Devoto
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Rampichini
authors.affiliation: Department of Biomedical Sciences for Health, University of Milan, Milan, Italy.|Center of Sport Medicine, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Don Gnocchi Foundation, Milan, Italy; and.
authors.forename: Fabio
authors.identifier: 0000-0002-4420-2611
authors.initials: F
authors.lastname: Esposito
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D052580:Muscle Stretching Exercises / Q000379:methods; D018482:Muscle, Skeletal / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology
chemical_list: D019344:Lactic Acid
keywords: mechanoreflex; metaboreflex; stretching