Effect of Stretching on Sport Injury Risk: a Review

Hart L

OBJECTIVE: Effect of Stretching on Sport Injury Risk: a Review To assess the evidence for the effectiveness of stretching for the prevention of injuries in sports.

DATA SOURCES: MEDLINE (1966 to September, 2002), Current Contents, Biomedical Collection, Dissertation Abstracts, the Cochrane Library, and SPORTDiscus were searched for articles in all languages using terms including stretching, flexibility, injury, epidemiology, and injury prevention. Reference lists were searched and experts contacted for further relevant studies.

STUDY SELECTION: Criteria for inclusion were randomized trials or cohort studies of interventions that included stretching compared with other interventions, with participants who were engaged in sporting or fitness activities. One author identified 361 articles reporting on flexibility, methods and effects of stretching, risk factors for injury, and injury prevention, of which 6 articles fulfilled the inclusion criteria for meta-analysis.

DATA EXTRACTION: Three independent reviewers blinded to the authors and institutions of the investigations assessed the methodologic quality of the studies (100-point scale) and reached consensus on disagreements. Details of study participants, interventions, and outcomes were extracted. Weighted pooled odds ratios were calculated for effects of interventions on an intention-to-treat basis.

MAIN RESULTS: Reduction in total injuries (shin splints, tibial stress reaction, sprains/strains, and lower-extremity and -limb injuries) with either stretching of specific leg-muscle groups or multiple muscle groups was not found in 5 controlled studies (odds ratio [OR] 0.93; 95% CI, 0.78 to 1.11). Reduction in injuries was not significantly greater for stretching of specific muscles (OR, 0.80; CI, 0.54-1.14) or multiple muscle groups (OR, 0.96; CI, 0.71-1.28). Combining the 3 ratings of methodologic quality, median scores were 29 to 60/100. After adjustment for confounders, low quality studies did not show a greater reduction in injuries with stretching (OR, 0.88; CI, 0.67-1.15) compared with high quality studies (OR, 0.97; CI, 0.77-1.22). Stretching to improve flexibility, adverse effects of stretching, and effects of warm up were not assessed by appropriate intervention studies.

CONCLUSION: Limited evidence showed stretching had no effect in reducing injuries.

Clinical Journal of Sport Medicine 2005 Mar;15(2):113. – abstract

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Filed under: Injuries, Review article , injury prevention, review, Sport Injury, Stretching

The mechanisms of massage and effects on performance, muscle recovery and injury prevention

Weerapong P, Hume PA, Kolt GS

Many coaches, athletes and sports medicine personnel hold the belief, based on observations and experiences, that massage can provide several benefits to the body such as increased blood flow, reduced muscle tension and neurological excitability, and an increased sense of well-being. Massage can produce mechanical pressure, which is expected to increase muscle compliance resulting in increased range of joint motion, decreased passive stiffness and decreased active stiffness (biomechanical mechanisms). Mechanical pressure might help to increase blood flow by increasing the arteriolar pressure, as well as increasing muscle temperature from rubbing. Depending on the massage technique, mechanical pressure on the muscle is expected to increase or decrease neural excitability as measured by the Hoffman reflex (neurological mechanisms). Changes in parasympathetic activity (as measured by heart rate, blood pressure and heart rate variability) and hormonal levels (as measured by cortisol levels) following massage result in a relaxation response (physiological mechanisms). A reduction in anxiety and an improvement in mood state also cause relaxation (psychological mechanisms) after massage. Therefore, these benefits of massage are expected to help athletes by enhancing performance and reducing injury risk. However, limited research has investigated the effects of pre-exercise massage on performance and injury prevention. Massage between events is widely investigated because it is believed that massage might help to enhance recovery and prepare athletes for the next event. Unfortunately, very little scientific data has supported this claim. The majority of research on psychological effects of massage has concluded that massage produces positive effects on recovery (psychological mechanisms). Post-exercise massage has been shown to reduce the severity of muscle soreness but massage has no effects on muscle functional loss. Notwithstanding the belief that massage has benefits for athletes, the effects of different types of massage (e.g. petrissage, effleurage, friction) or the appropriate timing of massage (pre-exercise vs post-exercise) on performance, recovery from injury, or as an injury prevention method are not clear. Explanations are lacking, as the mechanisms of each massage technique have not been widely investigated. Therefore, this article discusses the possible mechanisms of massage and provides a discussion of the limited evidence of massage on performance, recovery and muscle injury prevention. The limitations of previous research are described and further research is recommended.

Sports Medicine – 2005;35(3):235-56 – abstract

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Filed under: Massage, Prevention, Recovery, Recovery massage, Review article , Massage, muscle injury prevention, performance, Recovery

Mechanical supports for acute, severe ankle sprain: a pragmatic, multicentre, randomised controlled trial

SE Lamb , JL Marsh, JL Hutton, R Nakash , MW Cooke

Background

Severe ankle sprains are a common presentation in emergency departments in the UK. We aimed to assess the effectiveness of three different mechanical supports (Aircast brace, Bledsoe boot, or 10-day below-knee cast) compared with that of a double-layer tubular compression bandage in promoting recovery after severe ankle sprains.

Methods

We did a pragmatic, multicentre randomised trial with blinded assessment of outcome. 584 participants with severe ankle sprain were recruited between April, 2003, and July, 2005, from eight emergency departments across the UK. Participants were provided with a mechanical support within the first 3 days of attendance by a trained health-care professional, and given advice on reducing swelling and pain. Functional outcomes were measured over 9 months. The primary outcome was quality of ankle function at 3 months, measured using the Foot and Ankle Score; analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN37807450.

Results

Patients who received the below-knee cast had a more rapid recovery than those given the tubular compression bandage. We noted clinically important benefits at 3 months in quality of ankle function with the cast compared with tubular compression bandage (mean difference 9%; 95% CI 2·4—15·0), as well as in pain, symptoms, and activity. The mean difference in quality of ankle function between Aircast brace and tubular compression bandage was 8%; 95% CI 1·8—14·2, but there were little differences for pain, symptoms, and activity. Bledsoe boots offered no benefit over tubular compression bandage, which was the least effective treatment throughout the recovery period. There were no significant differences between tubular compression bandage and the other treatments at 9 months. Side-effects were rare with no discernible differences between treatments. Reported events (all treatments combined) were cellulitis (two cases), pulmonary embolus (two cases), and deep-vein thrombosis (three cases).

Interpretation

A short period of immobilisation in a below-knee cast or Aircast results in faster recovery than if the patient is only given tubular compression bandage. We recommend below-knee casts because they show the widest range of benefit.

The Lancet, Volume 373, Issue 9663, Pages 575 – 581, 14 February 2009 – abstract

doi:10.1016/S0140-6736(09)60206-3

Filed under: Injuries, Joints

Preventing Hamstring Injuries in Sport

Brughelli M, Cronin  J

Summary
Hamstring injuries can be devastating for athletes and sports teams. Recent advances in technology have greatly enhanced our understanding of how and why hamstring injuries occur. Based on this information, professional sports teams have implemented various training interventions in an attempt to reduce the rate of hamstring injuries with varying success. Reviewing the recent literature on hamstring injuries and the studies that have reported decreases in injury rates could give further insight into how hamstring injures can be prevented and thus is the focus of this article.

CONCLUSIONS

Hamstring injury rates can be reduced if an appropriate eccentric exercise protocol is followed. The exercises presented in this article have been developed based on the current literature that has shown increases in optimum length of tension development and reductions in hamstring injury rates. In addition to the reductions in injuries, a few studies have reported that hamstring injuries were less severe after an eccentric exercise protocol. Furthermore, the inclusion of such eccentric exercises may accelerate the recovery from hamstring injury and return to play. Both contentions, however, must be monitored in some fashion to be certain of the efficacy of the inclusion of eccentric exercises. These new and alternative exercises are not meant to replace any other modes or methods of training. Instead, they can simply be added to current training programs. The addition of 2 eccentric exercises per week (1 per session) should be an easy adjustment to the training program, which could lead to dramatic decreases in muscle strain injury rates.

Strength and Conditioning Journal:Volume 30(1)February 2008pp 55-64 – abstract

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Filed under: Exercise, Injuries, Prevention, Soft-tissue injuries

Is ice right? Does cryotherapy improve outcome for acute soft tissue injury?

N C Collins

Aims: The use of ice or cryotherapy in the management of acute soft tissue injuries is widely accepted and widely practised. This review was conducted to examine the medical literature to investigate if there is evidence to support an improvement in clinical outcome following the use of ice or cryotherapy.

Methods: A comprehensive literature search was performed and all human and animal trials or systematic reviews pertaining to soft tissue trauma, ice or cryotherapy were assessed. The clinically relevant outcome measures were (1) a reduction in pain; (2) a reduction in swelling or oedema; (3) improved function; or (4) return to participation in normal activity.

Results: Six relevant trials in humans were identified, four of which lacked randomisation and blinding. There were two well conducted randomised controlled trials, one showing supportive evidence for the use of a cooling gel and the other not reaching statistical significance. Four animal studies showed that modest cooling reduced oedema but excessive or prolonged cooling is damaging. There were two systematic reviews, one of which was inconclusive and the other suggested that ice may hasten return to participation.

Conclusion: There is insufficient evidence to suggest that cryotherapy improves clinical outcome in the management of soft tissue injuries.

Emergency Medicine Journal 2008;25:65-68; doi:10.1136/emj.2007.051664 – abstract

Filed under: Ice, Soft-tissue injuries

The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome.

Fairclough, J; Hayashi, K; Toumi, H; Lyons, K et al

Iliotibial band (ITB) syndrome is a common overuse injury in runners and cyclists. It is regarded as a friction syndrome where the ITB rubs against (and ‘rolls over’) the lateral femoral epicondyle. Here, we re-evaluate the clinical anatomy of the region to challenge the view that the ITB moves antero-posteriorly over the epicondyle. Gross anatomical and microscopical studies were conducted on the distal portion of the ITB in 15 cadavers. This was complemented by magnetic resonance (MR) imaging of six asymptomatic volunteers and studies of two athletes with acute ITB syndrome. In all cadavers, the ITB was anchored to the distal femur by fibrous strands, associated with a layer of richly innervated and vascularized fat. In no cadaver, volunteer or patient was a bursa seen. The MR scans showed that the ITB was compressed against the epicondyle at 30° of knee flexion as a consequence of tibial internal rotation, but moved laterally in extension. MR signal changes in the patients with ITB syndrome were present in the region occupied by fat, deep to the ITB. The ITB is prevented from rolling over the epicondyle by its femoral anchorage and because it is a part of the fascia lata. We suggest that it creates the illusion of movement, because of changing tension in its anterior and posterior fibres during knee flexion. Thus, on anatomical grounds, ITB overuse injuries may be more likely to be associated with fat compression beneath the tract, rather than with repetitive friction as the knee flexes and extends.

Journal of Anatomy; Mar2006, Vol. 208 Issue 3, p309-316,

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Filed under: Injuries, Knee