Recently, there has been a shift from static stretching (SS) or proprioceptive neuromuscular facilitation (PNF) stretching within a warm-up to a greater emphasis on dynamic stretching (DS). The objective of this review was to compare the effects of SS, DS, and PNF on performance, range of motion (ROM), and injury prevention. The data indicated that SS- (-3.7%), DS- (+1.3%), and PNF- (-4.4%) induced performance changes were small to moderate with testing performed immediately after stretching, possibly because of reduced muscle activation after SS and PNF. A dose-response relationship illustrated greater performance deficits with ≥60 s (-4.6%) than with <60 s (-1.1%) SS per muscle group. Conversely, SS demonstrated a moderate (2.2%) performance benefit at longer muscle lengths. Testing was performed on average 3-5 min after stretching, and most studies did not include poststretching dynamic activities; when these activities were included, no clear performance effect was observed. DS produced small-to-moderate performance improvements when completed within minutes of physical activity. SS and PNF stretching had no clear effect on all-cause or overuse injuries; no data are available for DS. All forms of training induced ROM improvements, typically lasting <30 min. Changes may result from acute reductions in muscle and tendon stiffness or from neural adaptations causing an improved stretch tolerance. Considering the small-to-moderate changes immediately after stretching and the study limitations, stretching within a warm-up that includes additional poststretching dynamic activity is recommended for reducing muscle injuries and increasing joint ROM with inconsequential effects on subsequent athletic performance.

Acute effects of muscle stretching on physical performance, range of motion, and injury incidence in healthy active individuals: a systematic review

Introduction: Loading characteristics of stretching techniques likely influence the specific mechanisms responsible for acute increases in range of motion (ROM). Therefore, the effects of a version of contract–relax (CR) proprioceptive neuromuscular facilitation stretching, static stretching (SS), and maximal isometric contraction (Iso) interventions were studied in 17 healthy human volunteers. Methods: Passive ankle moment was recorded on an isokinetic dynamometer, with EMG recording from the triceps surae, simultaneous real-time motion analysis, and ultrasound-imaging-recorded gastrocnemius medialis muscle and Achilles tendon elongation. Subjects then performed each intervention randomly on separate days before reassessment. Results: Significant increases in dorsiflexion ROM (2.5°–5.3°; P 0.05), whereas significant reductions in muscle stiffness occurred after CR stretching and SS (16.0%–20.5%; P 0.05). Increases in peak passive moment (stretch tolerance) occurred after Iso (6.8%; P 0.05). Significant correlations (rs = 0.69–0.82; P < 0.01) were observed between changes in peak passive moment and maximal ROM under all conditions. Conclusions: Although similar ROM increases occur after Iso and SS, changes in muscle and tendon stiffness are distinct. Concomitant reductions in muscle and tendon stiffness after CR stretching suggest a broader adaptive response that likely explains its superior efficacy in acutely increasing ROM. Although mechanical changes appear tissue-specific between interventions, similar increases in stretch tolerance after all interventions are strongly correlated with changes in ROM.

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Effects of Contract-Relax, Static Stretching, and Isometric Contractions on Muscle-Tendon Mechanics.

Grabow, L, Young, JD, Alcock, LR, Quigley, PJ, Byrne, JM, Granacher, U, Skarabot, J, and Behm, DG. Higher quadriceps roller massage forces do not amplify range-of-motion increases nor impair strength and jump performance. J Strength Cond Res 32(11): 3059-3069, 2018-Roller massage (RM) has been reported to increase range of motion (ROM) without subsequent performance decrements. However, the effects of different rolling forces have not been examined. The purpose of this study was to compare the effects of sham (RMsham), moderate (RMmod), and high (RMhigh) RM forces, calculated relative to the individuals' pain perception, on ROM, strength, and jump parameters. Sixteen healthy individuals (27 ± 4 years) participated in this study. The intervention involved three 60-second quadriceps RM bouts with RMlow (3.9/10 ± 0.64 rating of perceived pain [RPP]), RMmod (6.2/10 ± 0.64 RPP), and RMhigh (8.2/10 ± 0.44 RPP) pain conditions, respectively. A within-subject design was used to assess dependent variables (active and passive knee flexion ROM, single-leg drop jump [DJ] height, DJ contact time, DJ performance index, maximum voluntary isometric contraction [MVIC] force, and force produced in the first 200 milliseconds [F200] of the knee extensors and flexors). A 2-way repeated measures analysis of variance showed a main effect of testing time in active (p 0.05, d = 0.33-0.84). Roller massage can be efficiently used to increase ROM without substantial pain and without subsequent performance impairments.

Higher Quadriceps Roller Massage Forces Do Not Amplify Range-of-Motion Increases nor Impair Strength and Jump Performance.

Background
Patients with COPD present a major recruitment of the inspiratory muscles, predisposing to chest incoordination, increasing the degree of dyspnea and impairing their exercise capacity Stretching techniques could decrease the respiratory muscle activity and improve their contractile capacity; however, the systemic effects of stretching remain unknown

/pdf/effects-of-aerobic-training-combined-with-respiratory-muscle-3qj5ly7y62.pdf

Effects of aerobic training combined with respiratory muscle stretching on the functional exercise capacity and thoracoabdominal kinematics in patients with COPD: a randomized and controlled trial

Introduction: The proprioceptive neuromuscular facilitation-concept (PNF-concept) is a widely used rehabilitation concept, and is in many countries part of the undergraduate curriculum of physiotherapy education. It is also offered in postgraduate training worldwide. The modern physiotherapist is confronted with the application of evidence-based practice; therefore, the aim of this review is to summarize the available evidence for this rehabilitation concept.Method: A search was completed using Pubmed, ScienceDirect, PEDro, Cochrane library and the International PNF Association website. An evidence-based practice approach has been promoted in the field of physiotherapy since the early 1990s, hence we limited the search from 1990 until 2014.Major findings: Seventy-four sources that were found were categorized in: (A) PNF philosophy, (B) PNF basic principles and procedures, (C) PNF techniques in rehabilitation. In the reviewed publications, a variety of indications and subject populations were identified in...

The proprioceptive neuromuscular facilitation-concept; the state of the evidence, a narrative review

Proprioceptive neuromuscular facilitation (PNF) is common practice for increasing range of motion, though little research has been done to evaluate theories behind it. The purpose of this study was to review possible mechanisms, proposed theories, and physiological changes that occur due to proprioceptive neuromuscular facilitation techniques. Four theoretical mechanisms were identified: autogenic inhibition, reciprocal inhibition, stress relaxation, and the gate control theory. The studies suggest that a combination of these four mechanisms enhance range of motion. When completed prior to exercise, proprioceptive neuromuscular facilitation decreases performance in maximal effort exercises. When this stretching technique is performed consistently and post exercise, it increases athletic performance, along with range of motion. Little investigation has been done regarding the theoretical mechanisms of proprioceptive neuromuscular facilitation, though four mechanisms were identified from the literature. As stated, the main goal of proprioceptive neuromuscular facilitation is to increase range of motion and performance. Studies found both of these to be true when completed under the correct conditions. These mechanisms were found to be plausible; however, further investigation needs to be conducted. All four mechanisms behind the stretching technique explain the reasoning behind the increase in range of motion, as well as in strength and athletic performance. Proprioceptive neuromuscular facilitation shows potential benefits if performed correctly and consistently.

https://www.degruyter.com/downloadpdf/j/hukin.2012.31.issue--1/v10078-012-0011-y/v10078-012-0011-y.xml

Wyatt O. Briggs

Papers

Proprioceptive Neuromuscular Facilitation (PNF): Its Mechanisms and Effects on Range of Motion and Muscular Function