Scientific Rationales for Stretching Information
Stretching for Contracture Prevention and Improvement
Contractures are neurological problems that reduce the range of motion of a joint. Once it happens, it takes time and effort to improve, so prevention is always considered, and one of the most common methods is stretching.
One of the most common methods is stretching. Here is a research paper on the topic.
The study
49 studies with 2135 participants met the selection criteria.
None of the studies involved stretching for more than 7 months.
More than half of the studies (51%) had a low risk of selection bias.
All studies had a risk of detection bias for self-reported outcomes such as pain, and a risk of performance bias due to the difficulty of blinding the intervention. The effects of these biases are insignificant, given that there is little benefit from the treatment. There was high quality evidence that stretching did not have a clinically important short-term effect on joint mobility in people with neurological conditions.
There are no trials that have examined the short-term effects of stretching on quality of life or participation limitations in people with neurological conditions.
Five studies with 145 participants reported eight adverse events, including skin breakdown, bruising, blistering, and pain, but these data could not be statistically analyzed.
In people with non-neurological conditions, there was high quality evidence that stretching had no clinically important short-term effects on pain.
Conclusion.
There was high quality evidence that stretching did not have a clinically important effect on joint mobility in people with and without neurological conditions when stretching was performed at less than 7 months. Sensitivity analysis shows that results are robust in studies with risk of selection and detection bias compared to studies with low risk of bias. Subgroup analysis also suggests that the effects of stretching are consistent across people with different types of neurological or non-neurological conditions; the effects of stretching performed for longer than seven months have not been investigated. There was moderate and high quality evidence that stretching had no clinically important short-term effects on quality of life or pain in people with non-neurological conditions, respectively.
Harvey LA, Catalinick OM, Herbert RD, Moseley AM, Runnin NA, Schuler K. Stretching for the treatment and prevention of contractures. Cochrane Database of Systematic Reviews 2017, Issue 1. Art. no.: CD007455. DOI:. 10.1002 / 14651858.CD007455.pub3.
Rehabilitation of hamstring injuries
Since hamstring injuries are common in sports, it is essential for health care professionals to learn how to rehabilitate the injured hamstring.
The following is a research paper on the scope of rehabilitation that can be done by physical therapy.
The study
The review included two trials with a total of 104 participants.
One trial assessed stretching once a day and additional (four times a day) and the other trial assessed motor dysfunction and stretching and strengthening exercises.
The first trial, involving 80 elite athletes, suggested that additional stretching could reduce the time to return to full activity. A second trial involving 24 participants from diverse sports backgrounds found no conclusive evidence of a difference.
However, an 8% reduction in re-injury rate was reported versus 64% when using the exercise for motor dysfunction.
Conclusion.
Most physical therapy techniques proposed for the rehabilitation of hamstring injuries have not been evaluated using randomized trials. Those with only a single study with a limited range of participants and results. There is limited evidence to suggest that increasing the frequency of hamstring stretching exercises can reduce recovery time in elite athletes. From another small study of mixed athletes, there is preliminary evidence to suggest that exercises to correct motor dysfunction can reduce the time to return to full activity and the risk of re-injury. Further research is needed to confirm these findings. Until further evidence becomes available, current practice and widely published rehabilitation protocols cannot be supported or refuted.
Mason DL, Dickens VA, Vail A. Rehabilitation of hamstring injuries. A Systematic Review 2012, No. 12 Cochrane Database. Art. No.: CD004575. doi: 10.1002 / 14651858.CD004575.pub3.
Preventing Hamstring Injuries
Is there evidence for injury prevention methods? The following is an introduction to the topic.
The Study
Seven randomized controlled trials involving 1919 participants were included.
All trials involved people, mostly young adults, participating in regular sports activities. Some of the trials were compromised by inadequate methodology, including lack of blinding and incomplete outcome data.
Four trials, including 287 participants, examined interventions aimed directly at preventing hamstring injuries.
Three of these trials that tested hamstring strengthening protocols had conflicting findings, with one small trial showing benefit. The other two trials showed no benefit with a higher incidence of hamstring injury in the intervention group.
Hamstring injury findings did not reach statistical significance.
In the three trials testing interventions to prevent lower extremity injuries for which hamstring injury data were available, no statistically significant effect of hamstring injury was found for either the intrinsic receptivity protocol (two cluster-randomized trials) or the warm-up/cooldown and stretching protocol (one trial).
Conclusion.
There is insufficient evidence from randomized controlled trials to draw conclusions about the effectiveness of interventions used to prevent hamstring injuries in people participating in football or other high-risk activities. The findings of manual therapy need to be confirmed.
Goldman EF, Jones DE. Interventions to prevent hamstring injury. Cochrane Database of Systematic Reviews 2010, No. 1. Number: CD006782. doi: 10.1002 / 14651858.CD006782.pub2.
Stretching Before and After Exercise to Prevent Muscle Soreness
Can stretching before and after exercise prevent muscle soreness? The following is an introduction to the evidence.
The studies
Twelve studies were included in the review.
Two new studies were incorporated in this update (2011).
One of the new studies was a large field-based trial that included 2377 participants, of whom 1220 were assigned to stretch. The other 11 studies were all small, with 10 to 30 participants undergoing the stretching condition.
Ten of the studies were laboratory-based, while the other two were field-based.
All studies were subjected to moderate or high risk of bias. The quality of evidence was low to moderate.
The consistency of results across studies was high.
Pooled estimates showed that pre-exercise stretching reduced post-exercise 1-day pain by an average of 0.5 points on a 100-point scale.
Post-exercise stretching reduced post-exercise 1-day pain by an average of 1 point on a 100-point scale. A similar effect was evident half a day to three days after exercise. One large study showed that stretching before and after exercise reduced peak weekly pain by an average of 4 points on a 100-point scale.
This effect, while statistically significant, is very small.
Conclusion.
Evidence from randomized studies suggests that muscle stretching performed before, after, and after exercise does not produce a clinically important reduction in delayed onset muscle soreness in healthy adults.
Herbert RD, de Noronha M, Kamper SJ. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database of Systematic Reviews 2011, No. 7. Number: CD004577. doi: 10.1002 / 14651858.CD004577.pub3.
Not helpful in preventing sprains
Does it help in the act of sprain prevention? Here is a study that investigated it.
The study
The study aimed to investigate the acute and chronic effects of dynamic stretching on the anterior response properties of the peroneus brevis and tibialis anterior muscles.
A total of 21 male athletes (mean age 22.6 years, range 20-30 years) were randomly divided into two groups: a dynamic stretching group (n = 11) and a control group (n = 10).
Participants in the dynamic stretching group performed stretching exercises for the external ankle and dorsiflexor muscles five days a week for six weeks.
Response characteristics of the peroneal and tibialis muscles were assessed at baseline (twice for acute effects) and at the end of the intervention.
Electromyographic activity parameters, including muscle reaction time, reaction duration, and magnitude of response, were measured using the ankle inversion tilt platform. There were no significant differences in the acute and chronic effects of dynamic stretching exercises on reaction time, reaction duration, and muscle activity of the peroneal and tibialis anterior muscles at the four positions of the ankle inversion simulation platform.
Şekir U, Arslan G, İlhan O, Akova B. Dynamic stretching does not affect peroneal and tibial muscle reaction properties. Turk J Phys Med Rehabil. 2019;65(3 ):259-267. published 2019 Apr 30. doi:10.5606/tftrd.2019.3179
How to Stretch Your Hamstrings Efficiently
There has been some research on the best method of stretching. Here is a study on the best way to stretch.
Contents of the study
The hamstrings play a major role in posture, and shortening or overstraining of the hamstrings can affect posture and cause musculoskeletal pain. The aim of the study was to develop a new approach to improve hamstring flexibility in young adults.
The single-blind randomized clinical trial included 60 participants aged 18-24 years, recruited from Hashemite University in Zarqa, Jordan.
Range of motion in knee extension was measured by flexing the hip 90° using a simple goniometer to detect the level of hamstring flexibility.
Participants received either passive hamstring stretching (PS) followed by two sets of 10 tibial neurodynamic techniques (ND), or PS followed by three sets of 10 repetitions of active knee extension-quadriceps activation (QA), or PS only.
Results showed that there was a significant improvement in hamstring flexibility in the QA group compared to the PS group. (13.4 ± 12.1° vs. 6.2 ± 6.4°, p = 0.05)
In the PS group, it was 6.2±6.4 (30.5±10.8° vs. 36.6±9.5°, p = 0.001).
9.3 ± 6.2 (26.7 ± 10.9° vs. 36.0 ± 9.5°, p = 0.001) for the ND group.
In the QA group, the results were 13.4 ± 12.1 (20.3 ± 9.0° vs. 33.4 ± 8.9°, p = 0.001).
The results were as follows.
Considerations
Passive hamstring stretch
The participant was placed in a supine position, hip flexed 90°, and stretched by the therapist to the maximum level of passive knee extension allowed.
The stretching was sustained for 30 seconds/time.
Tibial nerve neurodynamic technique after PS
The participant was placed in the supine position, PS was performed, and the hips were made to bend.
Next, a sliding glide mechanism was applied to the tibial nerve, and repetitive ankle dorsiflexion with abduction was performed in synchronization with knee flexion-extension.
The ankle and knee positions were manipulated to glide the tibial nerve, which was performed at 10 repetitions/2 sets.
Activation of the quadriceps muscle after PS
After the participants underwent PS, participants were asked to actively extend the knee joint while the hip joint was flexed 90°.
Dynamic knee extension was performed in sets of 10 repetitions/3 sets.
Activating the quadriceps and practicing stretching were the ones that resulted in different hamstring extension when compared to when they were not.
This may be due to the mutual inhibition effect.
Mutual inhibition occurs via the spinal primitive reflex arc when the antagonist muscle relaxes in response to the activation of the agonist muscle.
Thus, there was more inhibition of the antagonist muscle (hamstring) in the group that had quadriceps activation compared to the group that received only passive stretching.
Since no significant difference was obtained between PS only and hamstring stretching practiced with PS, ND, the conclusion of this study alone is that the stretching is better when PS is performed and the quadriceps is activated.
This is a method that is easy to use in clinical practice, so I want to try it! This is a method that I would like to use, but medical professionals who like to feel "in the know" such as ND may be practicing it.
Alshammari F, Alzoghbieh E, Abu Kabar M, Hawamdeh M. A novel approach to improve hamstring flexibility: A single-blinded randomised clinical trial. Afr J Physiother. 2019;75(1):465. published 2019 Apr 23. doi:10.4102/sajp.v75i1.465
Nervous System Stretches for Hamstrings
In another article, we discussed stretching of the hamstrings, but the research presented here is based on a different technique that has been performed on wrestlers.
The study
The purpose of this study was to compare the short-term effects of sciatic nerve nerve sliding and nerve stretching exercises on hamstring muscle length and functional flexibility in wrestlers. Seventy-four wrestlers were included as participants in the study.
The athletes were randomly divided into two groups
Neurosliding group
Neural stretching group
Hamstring flexibility and functional flexibility were assessed using the Active Knee Extension Limitation (AKEL) angle and the Sit and Reach (SR) test one day before and immediately after the neural mobilization exercise, respectively.
A three-way repeated measures analysis of variance was performed to examine the effects of type of mobilization, time, and gender on interest in the AKEL right leg, AKEL left leg, and SR tests.
AKEL right leg (F = 59.886, P = .001)
AKEL left leg (F = 31.896, P = 0.001)
For the SR test (F = 22.630 ), it was determined that there was a statistically significant difference between the pre-mobilization and post-mobilization outcome measures. There is no statistically significant difference between males and females by these three measurements because the nerve sliding and nerve stretching exercises to the sciatic nerve of the wrestlers were effective in increasing flexibility and function of the hamstring and were not superior to each other.
What kind of stretching?
Neural Sliding
The starting limb position was with both hands on the back and feet positioned high enough so that they did not touch the ground.
In the first phase, the athlete was asked to dorsiflex the ankle while extending the limb and knee. In the second phase, after waiting one second in the first phase, the athlete was asked to flex the neck in head and neck flexion, simultaneously flexing the knee and bringing the ankle into plantar flexion.
Care must be taken when flexing the thoracolumbar region.
One repetition was completed in a total of 2 seconds, and a total of 30 repetitions of the exercise were performed in sets of 60 seconds.
Nerve stretch
Begin in the same starting limb position as the neural sliding.
In the first phase, the athlete was asked to flex the neck while simultaneously extending the knee and dorsiflexing the ankle.
After holding for one second, the athlete was asked to return the neck and simultaneously flex the knee and return the ankle.
A total of 2 seconds was required to complete one repetition, and the exercise was performed in sets of 30 repetitions for 60 seconds.
Care must be taken when flexing the thoracolumbar region.
Balcı A, Ünüvar E, Akınoğlu B, Kocahan T. The effect of different neural mobilization exercises on hamstring flexibility and functional flexibility in wrestlers. J Exerc Rehabil. 2020;16(6):503-509. published 2020 Dec 28. doi:10.12965/jer.2040700.350
Baseball and hip stiffness
In order to prevent shoulder and elbow injuries in baseball, hip flexibility is necessary. I wondered. In fact, I have never encountered a clinical case where the ability to spread the legs led to the prevention of shoulder or elbow injuries, and there are also examples of people with stiff hips who have never suffered shoulder or elbow injuries.
The study presented here was investigating such a relationship and which part of the hip joint's range of motion limitation leads to injury.
The study
Shoulder and elbow injuries have become a major problem for baseball players, and upper extremity strain has sometimes been reported as a risk factor for shoulder and elbow injuries in elementary and middle school students.
However, little research has been done to investigate the relationship between decreased hip range of motion (ROM) and shoulder and elbow injuries.
The purpose of this study was to prospectively investigate the relationship between hip ROM and pitching-related shoulder and elbow injuries in elementary and middle school baseball players. It was hypothesized that players with unrestricted hip ROM would have a lower risk of upper extremity injuries.
The study included 263 baseball players in the city and the following physical parameters were assessed
1: Hip flexion ROM measured in the supine position
2: Internal and external rotation of the hip in the supine position
At the end of the season, players completed a questionnaire about their shoulder and elbow injuries.
For comparison, players were classified as injured (unable to play for more than 8 days due to shoulder or elbow problems) or uninjured.
As a result, 52 players sustained shoulder or elbow injuries during the season.
Comparing the injured and non-injured groups, there was a significant decrease in dominant side hip flexion (121.5° vs. 126.7°), non-dominant side hip flexion (119.6° vs. 126.0), and dominant side internal rotation (52.5° vs. 56.8°) in the injured group.
Discussion
As a research model, there are several areas that are questionable. The study was a prospective study, so it is difficult to draw definite conclusions.
Injury predictors included limited hip flexion and internal rotation, and height and weight gain were also considered to be good predictors.
However, looking at the angle of the key range of motion, the angle could not be described as restricted? It is not an angle that can be said to be "restricted", and I think it can be judged as not a bad angle as a reference range of motion.
And since the paper does not follow up on whether the reason for the injury was due to limited range of motion of the hip joint, it only explains that the result of the injury was such a difference in range of motion.
In the paper, it seems that there was no investigation of the injury history, so the research is full of points to ponder. This means that it may not be possible to say that limited range of motion leads to injury.
Hamano N, Shitara H, Tajika T, et al. Relationship Between Upper Limb Injuries and Hip Range of Motion in Elementary and Junior High School Baseball Players. Orthop J Sports Med. 2021;9(2):2325967120970916. Published 2021 Feb 10. doi:10.1177/2325967120970916
