Page 65 - 《运动与健康科学》(英文)2024年第2期

TaggedAPTARAEndStretch training effects on flexibility 187
rehabilitation. The PNF technique can be divided into various guidelines and the suggestions for systematic reviews with
27
sub-techniques. In the passive techniques (“contractrelax” or meta-analysis from Moher et al. TaggedAPTARAEnd
“holdrelax”), the target muscle is placed into a position of
stretch followed by a static contraction. The muscle is then TaggedAPTARAH22.1. Search strategyTaggedAPTARAEnd
passively moved into a greater position of stretch. In the active
TaggedAPTARAPAn electronic literature search was performed in PubMed,
technique (“contractrelaxantagonistcontract”), the final
Scopus, Web of Science, and SportDiscus. Papers published
passive stretch is exchanged by an active contraction of the antag- through September 2022 were considered for inclusion. Using
4
onist, which stretches the target muscle. Due to the different
AND and OR Boolean operators, a systematic search was
stimuli applied in the various stretching techniques, it is expected
conducted using the following keywords: flexibility, “range of
that changes in ROM due to long-term stretch training can be
motion”, extensibility, and stretch*. In addition to the afore-
explained by different adaptations within the muscletendon mentioned keywords, the studies were filtered using the subse-
unit 13,19,20 and/or by changes in stretch or pain perception. 8,13
quent keywords to include controlled trials: “randomized
However, to date it is not clear which stretching technique will
controlled trial”, “controlled clinical trial”, “randomized”,
result in the highest ROM gains over the long term.TaggedAPTARAEnd
“placebo”, “randomly”, and “trial”. Furthermore, to exclude
TaggedAPTARAPBesides stretching technique, stretch intensity may be
animal studies we added a NOT operator with the following
another important factor underlying the extent of gains in ROM.
MeSH Term “exp animals/not humans”. For example, the
In general, stretch intensity can be divided into: (a) below point
following search query was used in PubMed: ((((“flexibility”
of discomfort (i.e., low-intensity stretching) and (b) until or at
17 (Title/Abstract)) OR (“range of motion”(Title/Abstract))) OR
the point of discomfort (i.e., high-intensity stretching).
(“extensibility”(Title/Abstract))) AND (“stretch*”(Title/
Although it was reported that a single (acute) bout of high-inten-
Abstract))) AND ((((((((“randomized controlled trial”(Publica-
sity stretching exercise is more favorable compared to low-in- tion Type)) OR (“controlled clinical trial”(Publication Type)))
tensity stretching with regard to ROM gains, 21,22 this is not
OR (“randomized”(Title/Abstract))) OR (“placebo”(Title/
clear yet for training (i.e., long-term, chronic) studies. While 1
Abstract))) OR (“clinical trials as topic”(MeSH Terms))) OR
study reported higher gains with a more intense stretching (“randomly”(Title/Abstract))) OR (“trial”(Title/Abstract)))
approach compared to low-intensity stretch training, 17 others NOT (exp animals/not humans(MeSH Terms))). The systema-
showed no such differences. 21,23 Thus, it would be important to
tic search was conducted by 8 independent researchers (SA,
perform a meta-analytic analysis to point out whether painful,
SHA, AD, AZ, RG, CE, CS, and AG). Initially, articles were
uncomfortable, or rather unpleasant stretching sensations are
screened by title and abstract. If the content remained unclear,
required to get the highest chronic gains in joint ROM.TaggedAPTARAEnd
the full text was retrieved for further screening, and relevant
TaggedAPTARAPIn addition to stretching technique and intensity, sex-specific
papers were identified. Following this screening process, the
adaptations resulting from stretch training might be relevant.
independent researchers compared their findings. Disagree-
Since most existing studies with sport science-related research ments were resolved by jointly reassessing the studies against
questions are biased towards male participants, 24 it will be
the eligibility criteria.TaggedAPTARAEnd
important to collect evidence from both sexes. Although it is
well understood that muscle function and structure differ
between males and females, 7,25 it is not yet well understood TaggedAPTARAH22.2. Inclusion and exclusion criteriaTaggedAPTARAEnd
whether sex-specific adaptations exist as a result of stretch TaggedAPTARAPThis review considered studies that investigated the training
effects of stretching on joint ROM in healthy participants. The
training.TaggedAPTARAEnd
TaggedAPTARAPIt is well known that stretch training can increase ROM in studies were included when they were either randomized
26
both sedentary and athletic populations. However, it is not controlled trials or controlled trials with an intervention dura-
yet well understood whether such increases are pronounced in tion 2 weeks. 28 This means that we excluded studies dealing
any of these groups more than others. Additionally, less data is with the acute effects of stretching (or interventions shorter
available on muscle-specific or age-specific responses. Thus, it than 2 weeks), those that investigated any combined treatment
will be important to summarize all existing evidence and to (e.g., stretching and strength training), and those that had
another treatment as the control condition (e.g., foam roller).
calculate and compare the respective effect sizes (ESs).TaggedAPTARAEnd
TaggedAPTARAPTherefore, the purpose of this meta-analysis was to investi- Moreover, we excluded review papers, case reports, special
gate the effects of stretch training (2 weeks) on joint ROM in communications, letters to the editor, invited commentaries,
healthy participants. Furthermore, we aimed to investigate the
conference papers, and theses.TaggedAPTARAEnd
influence of potential moderating factors, such as stretching
technique, intensity, duration, frequency, and muscles
TaggedAPTARAH22.3. Extraction of the dataTaggedAPTARAEnd
stretched, as well as sex-specific, age-specific, and/or trained
TaggedAPTARAPWe extracted the following data from included papers: the
state-specific adaptations to >2 weeks of stretch training.TaggedAPTARAEnd
characteristics of the participants (i.e., age, trained state, sex),
the sample size, the characteristics of the intervention (i.e.,
TaggedAPTARAH12. MethodsTaggedAPTARAEnd
stretch per bout, stretch duration per week, stretch frequency
TaggedAPTARAPThis review was conducted according to the Preferred per week, stretch technique, stretch intensity, muscle stretched,
Reporting Items for Systematic reviews and Meta-Analyses muscle tested, supervision of the stretch intervention), and the