Epidemiology of muscle injuries in professional football (soccer)

Muscle injuries of the lower extremity: a comparison between young and old male elite soccer players

PURPOSE

The aim of this study was to make a comparison between players in two age groups in an elite male soccer team regarding injury localisation within the muscle-tendon unit, injury size and muscle group in terms of muscle injuries of the lower extremity.

METHODS

Cohort study based on data collected from a Swedish elite male soccer team during the seasons 2007-2012. In total, 145 muscle injuries were included. Injury localisation to the tendon or muscle, the size of haematoma and the affected muscle group were assessed using ultrasound. Age comparison was made between younger players (≤23 years) and older players (>23 years).

RESULTS

No difference regarding injury localisation to either the tendon or the muscle, or the size of haematoma between the two age groups was found. However, the older group of players suffered a significantly higher number of injuries to the triceps surae than the younger players (p = 0.012).

CONCLUSIONS

In a Swedish team of male soccer players at elite level, there was no difference between players 23 years or younger and players older than 23 years, in terms of injury distribution to muscles or tendons. Players older than 23 years sustained more injuries to triceps surae when compared with players 23 years or younger. The clinical relevance is to pay attention to muscle function of triceps surae in older players and to screen those players who may need an injury prevention programme.

LEVEL OF EVIDENCE

II.

Large strengthening effect of a hip-flexor training programme: a randomized controlled trial

PURPOSE

To investigate the effect on hip-flexion strength of a 6-week hip-flexor training programme using elastic bands as resistance. We hypothesized that the training group, compared to a control group, would increase their hip-flexion strength more.

METHODS

Thirty-three healthy subjects (45 % females), 24(5) years of age, were included in a randomized controlled trial and allocated to heavy strength training of the hip-flexor muscles or to control (no strength training). Strength training of the hip-flexors (dominant leg) was performed three times 10 min per week for 6 weeks. The strength training group progressed from 15 repetition maximum (RM) (week 1) to 8 RM (week 6). Isometric hip-flexion strength (primary outcome) was measured by a blinded assessor using a reliable test procedure.

RESULTS

In the strength training group, the isometric hip-flexion strength of the trained leg increased by 17 %, (p < 0.001). The between-group difference in hip-flexion strength change in the trained leg (dominant leg, training group) versus the non-trained leg (dominant leg, control group) was significantly different from baseline to follow-up, corresponding to a mean change of 0.34 (95 % CI 0.17-0.52) Nm/kg, in favour of the strength training group (p < 0.001).

CONCLUSION

Simple hip-flexor strength training using elastic bands as external loading, for only 6 weeks, substantially improves hip-flexor muscle strength. This simple exercise programme seems promising for future prevention and treatment of acute and longstanding hip-flexor injuries, such as acute rectus femoris injuries and longstanding iliopsoas-related pain and impingement.

LEVEL OF EVIDENCE

I.

The correlation between the imaging characteristics of hamstring injury and time required before returning to sports: a literature review

Injuries to the hamstring muscles are common in athletes. Track and field, Australian football, American football and soccer are examples of sports where hamstring injuries are the most common. The purpose of this study was to investigate whether there is a correlation between a hamstring injury prognosis and its characteristics of imaging parameters. The literature search was performed in the databases PubMed and CINAHL, and eleven articles were included. Seven out of the 11 articles showed a correlation between the size of the hamstring injury and length of time required before returning to sports. Different authors have reported contrasting results about length of time required before returning to sports due to location of injury within specific muscle. Majority of the articles found hamstring strain correlated to an extended amount of time required before returning to sports.

Platelet-rich plasma in the treatment of acute hamstring injuries in professional football players

PURPOSE

muscle injuries have a high incidence in professional football and are responsible for the largest number of days lost from competition. Several in vitro studies have confirmed the positive role of platelet-rich plasma (PRP) in accelerating recovery and in promoting muscle regeneration, and not fibrosis, in the healing process. This study examines the results of intralesional administration of PRP in the treatment of primary hamstring injuries sustained by players belonging to a major league football club.

METHODS

twenty-five hamstring injuries (grade 2 according to MRI classification) sustained by professional football players during a 31-months observation period were treated with PRP and analyzed. Sport participation absence (SPA), in days, was considered to correspond to the healing time, and we also considered the re-injury rate, and tissue healing on MRI. The mean follow-up was 36.6 months (range 22-42).

RESULTS

there were no adverse events. The mean SPA for the treated muscle injuries was 36.76±19.02 days. The re-injury rate was 12%. Tissue healing, evaluated on MRI, was characterized by the presence of excellent repair tissue and a small scar.

CONCLUSIONS

this study confirmed the safety of PRP in treating hamstring lesions in a large series of professional football players. PRP-treated lesions did not heal more quickly than untreated lesions described in the literature, but they showed a smaller scar and excellent repair tissue.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Foot and Ankle Injuries in Professional Soccer Players: Diagnosis, Treatment, and Expectations

Soccer is one of the most popular sports in the world. It has undergone many changes in recent years, mainly because of increased physical demands, and this has led to an increased injury risk. Direct contact accounts for half of all injuries in both indoor and outdoor soccer and ankle sprains are the most common foot and ankle injury. There is a spectrum of foot and ankle injuries and their treatment should be individualized in these high-demand patients. An injury prevention program is also important and should the players, the trainer, responsible physician, and physical therapists.

Analysis of Injury Incidences in Male Professional Adult and Elite Youth Soccer Players: A Systematic Review

CONTEXT

The incidence of injury for elite youth and professional adult soccer players is an important concern, but the risk factors for these groups are different.

OBJECTIVE

To summarize and compare the injury incidences and injury characteristics of male professional adult and elite youth soccer players.

DATA SOURCES

We searched MEDLINE and Web of Science using the search terms elite, international, European, soccer, football, injury, injuries, epidemiology, incidence, prevalence, not female, not American football, and not rugby. We also used the search terms professional for studies on professional adult soccer players and high-level, soccer academy, youth, adolescent, and young for studies on elite youth soccer players.

STUDY SELECTION

Eligible studies were published in English, had a prospective cohort design, and had a minimum study period of 6 months. To ensure that injury data were assessed in relationship to the athlete's individual exposure, we included only studies that reported on injuries and documented exposure volume.

DATA EXTRACTION

Two independent reviewers applied the selection criteria and assessed the quality of the studies.

DATA SYNTHESIS

A total of 676 studies were retrieved from the literature search. Eighteen articles met the inclusion criteria: 6 for elite youth and 12 for professional adult soccer players.

CONCLUSIONS

Injury rates were higher for matches than for training for both youth and adult players. Youth players had a higher incidence of training injuries than professionals. Efforts must be made to reduce the overall injury rate in matches. Therefore, preventive interventions, such as adequately enforcing rules and focusing on fair play, must be analyzed and developed to reduce match-related injury incidences. Reducing training injuries should be a particular focus for youth soccer players.

A Prospective Analysis of the Injury Incidence of Young Male Professional Football Players on Artificial Turf

Background:

The effects of synthetic surfaces on the risk of injuries is still debated in literature and the majority of published data seems to be contradictory. For such reasons the understanding of injury incidence on such surfaces, especially in youth sport, is fundamental for injury prevention.

Objectives:

The aim of this study was to prospectively report the epidemiology of injuries in young football players, playing on artificial turfs, during a one sports season.

Patients and Methods:

80 young male football players (age 16.1 ± 3.7 years; height 174 ± 6.6 cm; weight 64.2 ± 6.3 kg) were enrolled in a prospective cohort study. The participants were then divided in two groups; the first included players age ranging from 17 to 19 (OP) whereas the second included players age ranging from 13 to 16 (YP). Injury incidence was recorded prospectively, according to the consensus statement for soccer.

Results:

A total of 107 injuries (35 from the OP and 72 from the YP) were recorded during an exposure time of 83.760 hours (incidence 1.28/1000 per player hours); 22 during matches (incidence 2.84/1000 per player hours, 20.5%) and 85 during training (incidence 1.15/1000 per player hours, 79.5%). Thigh and groin were the most common injury locations (33.6% and 21.5%, respectively) while muscle injuries such as contractures and strains were the most common injury typologies (68.23%). No statistical differences between groups were displayed, except for the rate of severe injuries during matches, with the OP displaying slightly higher rates compared to the YP. Severe injuries accounted for 10.28% of the total injuries reported. The average time lost due to injuries was 14 days. Re-injuries accounted for 4.67% of all injuries sustained during the season.

Conclusions:

In professional youth soccer injury rates are reasonably low. Muscle injuries are the most common type of injuries while groin and thigh the most common locations. Artificial turf pitches don’t seem to contribute to injury incidence in young football players.

Impact of quadriceps strengthening on response to fatiguing exercise following ACL reconstruction

OBJECTIVES

Patients commonly experience altered response to fatiguing exercise after ACL reconstruction (ACLR). The objective of this study was to assess the impact of quadriceps strengthening on response to exercise after ACLR.

DESIGN

Clinical trial.

METHODS

Ten participants with a history of primary, unilateral ACLR (sex=9F/1M, age=21.0±2.8 years, BMI=23.7±2.7kg/m²) and 10 healthy participants (sex=9F/1M, age=22.2±3.2 years, BMI=23.8±3.9kg/m²) participated. ACLR participants completed a 2-week quadriceps strengthening intervention including 14 progressive strengthening exercise sessions. Normalized knee extension maximum voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps central activation ratio (%, CAR) were measured before and after a 30-minute fatiguing exercise protocol. ACLR participants completed testing before and after the 2-week intervention while control participants completed a single testing session.

RESULTS

The intervention significantly improved normalized knee extension MVIC torque (pre-intervention=1.85±0.67Nm/kg, post-intervention=2.09±0.81Nm/kg, p=0.04) and quadriceps CAR in the ACLR involved limb (pre-intervention=86.51±5.03%, post-intervention=92.94±5.99%, p=0.02). Quadriceps CAR (pre-intervention=1.13±9.04%, post-intervention=-3.97±4.59%, p=0.16) and normalized knee extension MVIC torque (pre-intervention=0.26±20.90%, post-intervention=-8.02±12.82%, p=0.30) response to exercise did not significantly change from pre-intervention to post-intervention conditions.

CONCLUSIONS

Two weeks of quadriceps strengthening reduced this between group difference in the involved limb which may indicate restoration of more optimal quadriceps neuromuscular function and increased demand on the quadriceps during physical activity.

Current concepts of inguinal-related and adductor-related groin pain

Groin pain encompasses a number of conditions from the lower abdomen, inguinal region, proximal adductors, hip joint, upper anterior thigh and perineum. The complexity of the anatomy, the heterogeneous terminology and the overlapping symptoms of different conditions that may co-exist epitomise the challenges in diagnosis and treatment. Inguinal-related and adductor-related pain is the most common cause of groin pain and will be discussed in this article.

Fracture epidemiology in male elite football players from 2001 to 2013: 'How long will this fracture keep me out?'

BACKGROUND

Determining fracture risk and rehabilitation periods after specific fractures in professional football is essential for team planning.

AIM

To identify fracture epidemiology and absences after different types of fractures in male professional football players.

METHODS

2439 players from 41 professional male teams in 10 countries were followed prospectively from 2001 to 2013. Team medical staff registered fractures, absences after fractures and player exposure.

RESULTS

364 fractures were recorded, with an incidence of 0.27/1000 h of exposure (95% CI 0.25 to 0.30). The incidence of traumatic fractures was 0.25 (0.22 to 0.27) and that of stress fractures was 0.03 (0.02 to 0.04). 45% of traumatic fractures and 86% of stress fractures affected the lower extremities. Absence after a fracture was 32 days (1-278) (median (range)), compared to that after a traumatic fracture of 30 days (1-278) and a stress fracture of 65 days (6-168) (p<0.001). Annual fracture incidence was stable during the study period (R(2)=0.051, b=-0.011 (95% CI -0.043 to 0.021)). Young players had a relative risk of 10.9 (3.3 to 35.6) of sustaining stress fractures compared to old players (p<0.01). The fracture incidence did not differ between individuals in different playing positions (p=0.10).

SUMMARY

A male professional football team can expect 1 to 2 fractures per season. There are more traumatic fractures than stress fractures; while most fractures affect the lower extremities, stress fractures yield longer absences than traumatic fractures and young players have more stress fractures than old players. There is no difference in risk among players at different playing positions.

The acute effect of match play on hamstring strength and lower limb flexibility in elite youth football players

The aim of this study was to investigate the effect of competitive football match play on hamstring strength and lower limb flexibility. Fifteen male international youth football players were included. Hamstring strength and associated pain ratings, ankle dorsiflexion, hip extension, knee extension and flexion range of motion were evaluated immediately post-match and at intervals of 24, 48, and 72 h post-match. Strength significantly reduced post-match (P < 0.01), mean difference -0.43 (CI₉₅ : -0.56, -0.30) and 24 h post (P < 0.05) mean difference -0.12 Nm/kg (CI₉₅ : -0.20, -0.04). The associated pain scores significantly increased at the post-match (P < 0.01, ES = 0.61) and 24 h (P < 0.01, ES = 0.55) time intervals. At the 48 and 72 h post-match tests no significant difference was found for strength or pain ratings. No significant differences were detected for any of the range of motion measures. Competitive football match play has a significant acute and transient effect on isometric hamstring strength and associated pain levels during resisted knee flexion in male international youth players. Range of motion measures appear to remain relatively unaffected by match play. Isometric hamstring strength testing and associated pain levels might be considered for inclusion in-season to monitor player's post-match hamstring recovery characteristics.

Changes in muscle activity after performing the FIFA 11+ programme part 2 for 4 weeks

Changes in muscle activity were evaluated by positron emission tomography-computed tomography (PET-CT) after performing part 2 of the Fédération Internationale de Football Association's 11+ programme (11+) for 4 weeks. Eleven males performed part 2 of the 11+ for 20 min before and after 37 MBq of (18)F-fluorodeoxyglucose (FDG) was injected intravenously. PET-CT images were obtained 50 min after FDG injection. The participants were then instructed to perform part 2 of the 11+ 3 times per week for 4 consecutive weeks, after which another set of PET-CT images was obtained following the same procedure. Regions of interest were defined within 30 muscles. The standardised uptake value (SUV) of FDG by muscle tissue per unit volume was calculated, and FDG accumulation was compared between pre- and post-training PET-CT results. Performing part 2 of the 11+ for 4 weeks increased mean SUV in the sartorius, semimembranosus, biceps femoris, abductor hallucis, and flexor hallucis brevis muscles (P < 0.05). In conclusion, routinely performing part 2 of the 11+ for 4 weeks increased glucose uptake related to muscle activity in the hamstrings and hallux muscles. We speculate that there is some possibility of this change of muscle activity contributing to a decrease in sports-related injuries.

Platelet-rich plasma (PRP) treatment of sports-related severe acute hamstring injuries

PURPOSE

hamstring injury is the most common musculoskeletal disorder and one of the main causes of missed sporting events. Shortening the time to return to play (TTRTP) is a priority for athletes and sports medicine practitioners.

HYPOTHESIS

platelet-rich plasma (PRP) injection at the site of severe acute hamstring injury increases the healing rate and shortens the TTRTP.

STUDY DESIGN

Cohort study.

METHODS

all patients with ultrasonography and MRI evidence of severe acute hamstring injury between January 2012 and March 2014 were offered PRP treatment. Those who accepted received a single intramuscular PRP injection within 8 days post-injury; the other patients served as controls. The same standardized rehabilitation program was used in both groups. A physical examination and ultrasonography were performed 10 and 30 days post-injury, then a phone interview 120 days post-injury, to determine the TTRTP at the pre-injury level.

RESULTS

of 34 patients, 15 received PRP and 19 did not. Mean TTRTP at the pre-injury level was 50.9±10.7 days in the PRP group and 52.8±15.7 days in the control group. The difference was not statistically significant.

CONCLUSION

a single intramuscular PRP injection did not shorten the TTRTP in sports people with severe acute hamstring injuries.

Altered mechanical interaction between rat plantar flexors due to changes in intermuscular connectivity

Connective tissue formation following muscle injury and remedial surgery may involve changes in the stiffness and configuration of the connective tissues linking adjacent muscles. We investigated changes in mechanical interaction of muscles by implanting either a tissue-integrating mesh (n = 8) or an adhesion barrier (n = 8) to respectively increase or decrease the intermuscular connectivity between soleus muscle (SO) and the lateral gastrocnemius and plantaris complex (LG+PL) of the rat. As a measure of mechanical interaction, changes in SO tendon forces and proximal-distal LG+PL force differences in response to lengthening LG+PL proximally were assessed 1 and 2 weeks post-surgery. The extent of mechanical interaction was doubled 1 week post-implantation of the tissue-integrating mesh compared to an unaffected compartment (n = 8), and was more than four times higher 2 weeks post-surgery. This was found only for maximally activated muscles, but not when passive. Implanting the adhesion barrier did not result in a reduction of the mechanical interaction between these muscles. Our findings indicate that the ratio of force transmitted via myofascial, rather than myotendinous pathways, can increase substantially when the connectivity between muscles is enhanced. This improves our understanding of the consequences of connective tissue formation at the muscle boundary on skeletal muscle function.

The within-match patterns of locomotor efficiency during professional soccer match play: Implications for injury risk?

OBJECTIVES

The principle aim of the current study was to examine within-match patterns of locomotor efficiency in professional soccer, determined as the ratio between tri-axial accelerometer data (PlayerLoad™) and locomotor activities. Between match variability and determinants of PlayerLoad™ during match play were also assessed.

DESIGN

A single cohort, observational study.

METHODS

Tri-axial accelerometer data (PlayerLoad™) was recorded during 86 competitive soccer matches in 63 English championship players (574 match observations). Accelerometer data accumulated (PlayerLoad Vector Magnitude [PLVM]) from the individual-component planes of PlayerLoad™ (anterior-posterior PlayerLoad™ [PLAP], medial-lateral PlayerLoad™ [PLML] and vertical PlayerLoad™ [PLV]), together with locomotor activity (Total Distance Covered [TDC]) were determined in 15-min segments. Locomotor efficiency was calculated using the ratio of PLVM and TDC (PlayerLoad™ per metre). The proportion of variance explaining the within-match trends in PLVM, PLAP, APML, APv, and TDC was determined owing to matches, individual players, and positional role.

RESULTS

PLVM, PLAP, APML, APv and TDC reduced after the initial 15-min match period (p=0.001; η(2)=0.22-0.43, large effects). PL:TDC increased in the last 15min of each half (p=0.001; η(2)=0.25, large effect). The variance in PLVM during soccer match-play was explained by individual players (63.9%; p=0.001) and between-match variation (21.6%; p=0.001), but not positional role (14.1%; p=0.364).

CONCLUSIONS

Locomotor efficiency is lower during the latter stages of each half of competitive soccer match-play, a trend synonymous with observations of increased injury incidence and fatigue in these periods. Locomotor efficiency may be a valuable metric to identify fatigue and heightened injury risk during soccer training and match-play.

Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.

Hamstring Muscle Injuries, a Rehabilitation Protocol Purpose

Context:

Hamstring acute muscle injuries are prevalent in several sports including AFL football (Australian Football League), sprinting and soccer, and are often associated with prolonged time away from sport.

Evidence Acquisition:

In response to this, research into prevention and management of hamstring injury has increased, but epidemiological data shows no decline in injury and re-injury rates, suggesting that rehabilitation programs and return to play (RTP) criteria have to be improved. There continues to be a lack of consensus regarding how to assess performance, recovery and readiness to RTP, following hamstring strain injury.

Results:

The aim of this paper was to propose rehabilitation protocol for hamstring muscle injuries based on current basic science and research knowledge regarding injury demographics and management options.

Conclusions:

Criteria-based (subjective and objective) progression through the rehabilitation program will be outlined along with exercises for each phase, from initial injury to RTP.

The efficacy of exercise in preventing injury in adult male football: a systematic review of randomised controlled trials

BACKGROUND

Injury prevention measures might reduce the impact of injury on footballers and football clubs. Increasing research has evaluated the use of exercise for injury prevention. However, research has focused on adolescent females. No high-quality systematic reviews have evaluated the efficacy of all forms of exercise on preventing injury in adult male football.

OBJECTIVE

Our objective was to conduct a systematic review to evaluate the efficacy of exercise in preventing injury in adult male football.

DATA SOURCES

Comprehensive searches of electronic databases CINAHL (Cumulative Index to Nursing and Allied Health Literature), MEDLINE, Embase, AMED (The Allied and Complementary Medicine Database), the Cochrane Central Register of Controlled Trials, PEDro (The Physiotherapy Evidence Database), SPORTDiscus™, the National Research Register, Current Controlled Trials website (York), and http://www.ClinicalTrials.gov were conducted using predefined search terms to identify relevant studies published up to 1 March 2013. Screening of references, searches of grey literature, and hand searches of relevant journals were also employed.

STUDY SELECTION

Included studies were randomized controlled trials using injury incidence as an outcome measure to evaluate the efficacy of an exercise intervention on uninjured male footballers aged 16 years and over. Articles not written in English were excluded.

DATA EXTRACTION

Two researchers independently searched data sources, screened studies for eligibility, evaluated risk of bias, and extracted data using predefined criteria.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias of included trials was assessed using the Cochrane Collaboration's tool for assessing risk of bias. There was insufficient trial comparability (outcome measures, interventions, injury type) for meta-analysis, and a qualitative analysis was performed.

RESULTS

Eight trials (n = 3,355) from five countries met the inclusion criteria. All trials were assessed as having a high risk of bias. Two trials reported statistically significant reductions in hamstring injuries with eccentric exercise, and two reported statistically significant reductions in recurrent ankle sprains with proprioceptive exercise. Four trials showed no statistically significant difference in injury incidence with exercise interventions targeting a range of injuries.

LIMITATIONS

Notable limitations of included trials included poor reporting and limited blinding. A high risk of bias and insufficient comparability across trials prevented quantitative data synthesis.

CONCLUSIONS

Limitations in the context of study quality and heterogeneity resulted in an inability to reach a clear conclusion regarding efficacy of exercise for injury prevention in adult male football. Future low risk of bias, properly powered, and comprehensively reported trials are warranted to evaluate the efficacy of exercise on injury prevention. The use of eccentric hamstring exercise for hamstring injury prevention and proprioceptive training for recurrent ankle sprain prevention might be a good focus for future trials, as existing trials with a high risk of bias suggest an effect.

Large eccentric strength increase using the Copenhagen Adduction exercise in football: A randomized controlled trial

Hip adductor injuries are frequent in football, and players with low adductor strength appear to be at increased risk of injury. High adductor muscle activity has been shown in the Copenhagen Adduction exercise (CA); however, an associated strength gain has not been investigated. This study aims to examine the eccentric hip adduction strength (EHAD) gain using the CA in-season. Two U-19 sub-elite football teams, including 24 football players, were randomized to either an 8-week supervised progressive training program in addition to the usual training (intervention) or to continue training as usual (control). EHAD, eccentric hip abduction strength (EHAB), and side-bridge endurance were measured using reliable test procedures at baseline and follow-up by a blinded tester. There was a significant interaction between group and time on EHAD, EHAB, and EHAD/EHAB ratio (P < 0.025). The intervention group demonstrated a 35.7% increase in EHAD (P < 0.001); a 20.3% increase in EHAB (P = 0.003), and 12.3% increase in EHAD/EHAB ratio (P = 0.019). No significant within-group differences were found in the control group (P > 0.335). Compliance was 91.25%, and median muscle soreness ranged from 0 to 2. The CA implemented in-season with an 8-week progressive training program elicited a large significant increase in EHAD, EHAB, and EHAD/EHAB ratio.

Successful return to high-level sports following early surgical repair of combined adductor complex and rectus abdominis avulsion

Hip and groin injuries are common in athletes who take part in high level sports. Adductor muscle tendon injuries represent a small but important number of these injuries. Avulsion of the tendons attached to the symphysis pubis has previously been described: these can be managed both operatively and non-operatively. We describe an uncommon variant of this injury, namely complete avulsion of the adductor sleeve complex: this includes adductor longus, pectineus and rectus abdominis. We go on to describe a surgical technique which promotes a full return to the pre-injury level of sporting activity.

Over a period of ten years, 15 high-level athletes with an MRI-confirmed acute adductor complex avulsion injury (six to 34 days old) underwent surgical repair. The operative procedure consisted of anatomical re-attachment of the avulsed tissues in each case and mesh reinforcement of the posterior inguinal wall in seven patients. All underwent a standardised rehabilitation programme, which was then individualised to be sport-specific.

One patient developed a superficial wound infection, which was successfully treated with antibiotics. Of the 15 patients, four complained of transient local numbness which resolved in all cases. All patients (including seven elite athletes) returned to their previous level of participation in sport.

Cite this article: Bone Joint J 2015;97-B:1488–92.

Efficacy of autologous platelet-rich plasma for the treatment of muscle rupture with haematoma: a multicentre, randomised, double-blind, placebo-controlled clinical trial

BACKGROUND

The goals of the treatment of muscle injuries are to shorten the time of healing and to avoid relapses. The aim of this study was to assess the efficacy of autologous platelet-rich plasma (PRP) in the healing of muscle injuries.

MATERIALS AND METHODS

A multicentre, randomised, double-blind, parallel, controlled clinical trial was conducted in 71 patients (81.8% males) aged 45.6 (SD=10.0) years with muscle tears in the legs and haematoma. The haematoma was evacuated in all patients. Thirty-three patients were randomised to a single dose of autologous PRP and 38 patients to simulation of PRP administration. The primary end-point was time to complete recovery of muscle injury. Secondary end-points were pain, relapses, ultrasound parameters, and adverse events. The total follow-up per patient was 12 months.

RESULTS

Time to complete recovery after the treatment was 31.63 days (SD=15.38) in the PRP group, and 38.43 days (SD=18.58) in the control group (p=0.261). Pain decreased over time in both groups without statistical differences between them. Eight patients relapsed (seven in the control group, and one in the PRP group). There were no adverse effects related to the interventions.

DISCUSSION

Autologous PRP did not significantly improve the time to healing compared to that in the control group.

Hip Pain in Athletes - When It is Not the Labrum

Hip pain is a relatively common complaint in sports. It is tempting to blame the athlete's symptoms on labral pathology. However, there is a high incidence of asymptomatic labral disease. Therefore, even when a labral tear is present, it may not be the underlying cause of the patient's pain. Clinicians should familiarize themselves with the large differential diagnosis for hip and pelvis pain to include nonmusculoskeletal pathology. This article reviews nonlabral causes of hip pain in athletes. For ease of classification, the hip is divided into anterior, lateral, and posterior regions.

EXTRACORPOREAL SHOCKWAVE TERAPY TO TREAT CHRONIC MUSCLE INJURY

Objective: To evaluate the low energy extracorporeal shock waves therapy (ESWT) associated with physical therapy in the treatment of chronic muscle injuries classified as grades 2 and 3 in the lower limbs of amateur athletes. Methods: Eight athletes presenting with lower limb muscle injury for more than three weeks were treated with physiotherapy and ESWT. We evaluated the following parameters during treatment: palpable gap, muscle strength, pain, and Tegner score, as well as ultrasound image features and the ability to return to sports practice. Results: The average time of the first evaluation of the injury was 8.75 weeks. All patients presented muscle strength grade V after eight weeks. The pain score evolved from 5.75 to 0.5 points of the visual analogue scale (VAS), at the end of the treatment. The Tegner score after treatment was six points on average. Patients returned to sports practice after 8.14 weeks. Conclusion: ESWT associated with physical therapy proved to be effective to treat long-term muscle injury, with good performance and the ability to return to sport practice for all patients. Level of Evidence IV, Case Series, Prospective Study.

Suture anchor repair of proximal rectus femoris avulsions in elite football players

PURPOSE

To report the results of suture anchor repair of proximal rectus femoris avulsions in elite football players.

METHODS

Four professional football players (first-team regulars of European first division football clubs) underwent suture anchor repair of complete proximal rectus femoris avulsions with significant tendon retraction. The following parameters were analysed: demographic data, mechanism of injury, type of injury, classification according to the Munich consensus statement, time between injury and surgery, time between surgery and full participation in training and availability for match and/or competition selection (return to play/RTP), and time between surgery and the comeback to the first official league match (return to competition/RTC). Radiographic evaluation was performed by magnetic resonance imaging (MRI) obtained pre-operatively and at 6 and 12 weeks post-operatively. All players were followed for at least 24 months after return to play to exclude recurrence.

RESULTS

Mean age at surgery was 30 ± 2 years. All injuries occurred while kicking a ball, with the dominant leg affected in all patients. The injury was considered acute in three cases and chronic in one case. According to the Munich classification, all injures were type 4. Mean time to surgery was 60 ± 88 days (range, 8-191), mean time to RTP was 111 ± 15 days (range, 100-134), and mean time to RTC was 140 ± 23 days (range, 114-166). Follow-up MRIs demonstrated anatomically reinserted tendons with decreasing signal intensity over time in all cases. After a mean follow-up of 35 ± 6 months, all players were still competing at the same level as before the injury without re-injury.

CONCLUSION

Suture anchor repair of proximal rectus femoris avulsions allows unrestricted return to play in professional elite football players. Return to play can be expected at approximately 16 weeks post-operatively.

Hamstrings strength imbalance in professional football (soccer) players in Australia

The aim of this study was to describe the isokinetic thigh muscle strength profile of professional male football players in Australia. Concentric (60° and 240°·s(-1)) and eccentric (30° and 120°·s(-1)) hamstrings and quadriceps isokinetic strength was measured with a HUMAC NORM dynamometer. The primary variables were bilateral concentric and eccentric hamstring and quadriceps peak torque ratios, concentric hamstring-quadriceps peak torque ratios, and mixed ratios (eccentric hamstring 30°·s(-1) ÷ concentric quadriceps 240°·s(-1)). Hamstring strength imbalance was defined as deficits in any 2 of: bilateral concentric hamstring peak torque ratio <0.86, bilateral eccentric hamstring peak torque ratio <0.86, concentric hamstring-quadriceps ratio <0.47, and mixed ratio <0.80. Fifty-five strength tests involving 42 players were conducted. Ten players (24%) were identified as having hamstring strength imbalance. Athletes with strength imbalance had significantly reduced concentric and eccentric bilateral hamstring peak torque ratios at all angular velocities tested; and reduced eccentric quadriceps peak torque (30°·s(-1)) in their stance leg, compared with those without strength imbalance. Approximately, 1 in 4 players had preseason hamstring strength imbalance; and all strength deficits were observed in the stance leg. Concentric and eccentric hamstrings strength imbalance may impact in-season football performance and could have implications for the future risk of injury.

Diagnosis of Acute Groin Injuries: A Prospective Study of 110 Athletes

BACKGROUND

Acute groin injuries are common in high-intensity sports, but there are insufficient data on injury characteristics such as injury mechanisms and clinical and radiological findings.

PURPOSE

To describe these characteristics in a cohort of athletes.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 110 male athletes (mean age, 25.6 ± 4.7 years) with sports-related acute groin pain were prospectively included within 7 days of injury from August 2012 to April 2014. Standardized history taking, a clinical examination, magnetic resonance imaging (MRI), and/or ultrasound (US) were performed.

RESULTS

The most frequent injury mechanism in soccer was kicking (40%), and change of direction was most frequent in other sports (31%). Clinically, adductor injuries accounted for 66% of all injuries and primarily involved the adductor longus on imaging (91% US, 93% MRI). The iliopsoas and proximal rectus femoris were also frequently injured according to all examination modalities (15%-25%). Acute injury findings were negative in 22% of the MRI and 25% of the US examinations. Of the clinically diagnosed adductor injuries, 3% (US) and 6% (MRI) showed a radiological injury in a different location compared with 35% to 46% for clinically diagnosed iliopsoas and proximal rectus femoris injuries.

CONCLUSION

Adductor injuries account for the majority of acute groin injuries. Iliopsoas and proximal rectus femoris injuries are also common. More than 1 in 5 injuries showed no imaging signs of an acute injury. Clinically diagnosed adductor injuries were often confirmed on imaging, whereas iliopsoas and rectus femoris injuries showed a different radiological injury location in more than one-third of the cases. The discrepancy between clinical and radiological findings should be considered when diagnosing acute groin injuries.

Return to Play After Soleus Muscle Injuries

Background

Soleus muscle injuries are common in different sports disciplines. The time required for recovery is often difficult to predict, and reinjury is common. The length of recovery time might be influenced by different variables, such as the involved part of the muscle.

Hypothesis

Injuries in the central aponeurosis have a worse prognosis than injuries of the lateral or medial aponeurosis as well as myofascial injuries.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 61 high-level or professional athletes from several sports disciplines (soccer, tennis, track and field, basketball, triathlon, and field hockey) were reviewed prospectively to determine the recovery time for soleus muscle injuries. Clinical and magnetic resonance imaging evaluation was performed on 44 soleus muscle injuries. The association between the different characteristics of the 5 typical muscle sites, including the anterior and posterior myofascial and the lateral, central, and medial aponeurosis disruption, as well as the injury recovery time, were determined. Recovery time was correlated with age, sport, extent of edema, volume, cross-sectional area, and retraction extension or gap.

Results

Of the 44 patients with muscle injuries who were analyzed, there were 32 (72.7%) strains affecting the myotendinous junction (MT) and 12 (23.7%) strains of the myofascial junction. There were 13 injuries involving the myotendinous medial (MTM), 7 affecting the MT central (MTC), 12 the MT lateral (MTL), 8 the myofascial anterior (MFA), and 4 the myofascial posterior (MFP). The median recovery time (±SD) for all injuries was 29.1 ± 18.8 days. There were no statistically significant differences between the myotendinous and myofascial injuries regarding recovery time. The site with the worst prognosis was the MTC aponeurosis, with a mean recovery time of 44.3 ± 23.0 days. The site with the best prognosis was the MTL, with a mean recovery time of 19.2 ± 13.5 days (P < .05). There was a statistically significant correlation between recovery time and age (P < .001) and between recovery time and the extent of retraction (P < .05).

Conclusion

Wide variation exists among the different types of soleus injuries and the corresponding recovery time for return to the same level of competitive sports. Injuries in the central aponeurosis have a significantly longer recovery time than do injuries in the lateral and medial aponeurosis and myofascial sites.

Quadriceps muscle function after exercise in men and women with a history of anterior cruciate ligament reconstruction

CONTEXT

Sex differences in lower extremity neuromuscular function have been reported after anterior cruciate ligament reconstruction (ACLR). Research evidence supports different levels of fatigability in men and women and between patients with ACLR and healthy controls. The influence of sex on the response to continuous exercise in patients with ACLR is not clear.

OBJECTIVE

To compare quadriceps neuromuscular function after exercise between men and women with ACLR.

DESIGN

Descriptive laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-six active volunteers (13 men [50%]: age = 24.1 ± 4.4 years, height = 179.1 ± 9.8 cm, mass = 80.1 ± 9.4 kg, months since surgery = 43.5 ± 37.0; 13 women [50%]: age = 24.2 ± 5.6 years, height = 163.0 ± 5.9 cm, mass = 62.3 ± 8.3 kg, months since surgery = 45.8 ± 42.7) with a history of unilateral primary ACLR at least 6 months earlier.

INTERVENTION(S)

Thirty minutes of continuous exercise comprising 5 separate 6-minute cycles, including 5 minutes of uphill walking and 1 minute of body-weight squatting and step-ups.

MAIN OUTCOME MEASURE(S)

Normalized knee-extension maximal voluntary isometric contraction torque, quadriceps superimposed-burst torque, and quadriceps central activation ratio before and after exercise. We performed separate 2 (sex: men, women) × 2 (time: preexercise, postexercise) repeated-measures analyses of variance for the 3 variables. Separate, independent-samples t tests were calculated to compare preexercise with postexercise change in all dependent variables between sexes.

RESULTS

A significant group-by-time interaction was present for knee-extension torque (P = .04). The percentage reduction in knee-extension maximal voluntary isometric contraction torque (men = 1.94%, women = -10.32%; P = .02) and quadriceps central activation ratio (men = -1.45%, women = -8.69%; P = .03) experienced by men was less than that observed in women.

CONCLUSIONS

In the presence of quadriceps dysfunction, female participants experienced greater-magnitude reductions in quadriceps function after 30 minutes of exercise than male participants. This indicates a reduced ability to absorb knee-joint loads, which may have significant implications for reinjury and joint osteoarthritis in women after ACLR.

Soccer-Related Injuries in Children and Adults Aged 5 to 49 Years in US Emergency Departments From 2000 to 2012

Background:

An increase in soccer-related injuries occurred in the United States between 2000 and 2012; however, most studies of soccer-related injuries have only examined the pediatric population and not adults.

Hypothesis:

The number of soccer injuries is increasing in both the pediatric and adult populations. There are differences in injury types and counts when comparing male and female players within various age groups.

Study Design:

Descriptive epidemiology study.

Level of Evidence:

Level 4.

Methods:

This retrospective analysis surveyed the US Consumer Product Safety Commission’s National Electronic Injury Surveillance System (NEISS) database from 2000 to 2012 for soccer-related injuries in children and adults aged 5 to 49 years.

Results:

From 2000 to 2012, there were an estimated 2,472,066 soccer-related injuries among 5- to 49-year-olds; 629,994 (25.5%) in adults (aged 20-49 years). The overall estimated pediatric injury count increased significantly over the time period (R² = 0.764, P < 0.001). In the 20- to 49-year age range, there was also a significant increase in the estimated number of injuries over the 13-year period, from 41,292 injuries in 2000 to 55,743 in 2012 (R² = 0.719, P < 0.001). The estimated injury counts for male players were significantly higher than female players in any given year for all age groups (P < 0.001). Girls aged 5 to 19 years were more likely to have lower extremity injuries than boys (odds ratio [OR], 1.256; 95% CI, 1.214-1.299; P < 0.001). The most common injuries reported were strain/sprains (33.3%), fractures (23.7%), and contusions and abrasions (17.4%) within the 5- to 49-year age category. In both sexes, strains and sprains were significantly lower among 5- to 19-year-olds in comparison with 20- to 49-year-olds (OR, 0.740; 95% CI, 0.714-0.766; P < 0.001).

Conclusion:

There are age- and sex-related differences in estimated injury count, body part injured, type of injury, and hospital admissions for soccer. Also, estimated injury count increased over the 2000 to 2012 time period.

Clinical Relevance:

This study demonstrates that there are differences between pediatric and adult injuries, based on sex, body part, type of injury, and hospital admissions.

Recovery kinetics of knee flexor and extensor strength after a football match

We examined the temporal changes of isokinetic strength performance of knee flexor (KF) and extensor (KE) strength after a football match. Players were randomly assigned to a control (N = 14, participated only in measurements and practices) or an experimental group (N = 20, participated also in a football match). Participants trained daily during the two days after the match. Match and training overload was monitored with GPS devices. Venous blood was sampled and muscle damage was assessed pre-match, post-match and at 12h, 36h and 60h post-match. Isometric strength as well as eccentric and concentric peak torque of knee flexors and extensors in both limbs (dominant and non-dominant) were measured on an isokinetic dynamometer at baseline and at 12h, 36h and 60h after the match. Functional (KF_ecc/KE_con) and conventional (KF_con/KE_con) ratios were then calculated. Only eccentric peak torque of knee flexors declined at 60h after the match in the control group. In the experimental group: a) isometric strength of knee extensors and knee flexors declined (P<0.05) at 12h (both limbs) and 36h (dominant limb only), b) eccentric and concentric peak torque of knee extensors and flexors declined (P<0.05) in both limbs for 36h at 60°/s and for 60h at 180°/s with eccentric peak torque of knee flexors demonstrating a greater (P<0.05) reduction than concentric peak torque, c) strength deterioration was greater (P<0.05) at 180°/s and in dominant limb, d) the functional ratio was more sensitive to match-induced fatigue demonstrating a more prolonged decline. Discriminant and regression analysis revealed that strength deterioration and recovery may be related to the amount of eccentric actions performed during the match and athletes' football-specific conditioning. Our data suggest that recovery kinetics of knee flexor and extensor strength after a football match demonstrate strength, limb and velocity specificity and may depend on match physical overload and players' physical conditioning level.

The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial

BACKGROUND

Hamstring injuries are the most common muscle injuries in soccer, and they have a high rate of recurrence. Eccentric hamstrings strength is recognized as an important modifiable risk factor. This led to the development of prevention exercises such as the nordic hamstring exercise (NHE). The effectiveness of the NHE on hamstring injury prevention has never been investigated in amateur soccer.

PURPOSE

To investigate the preventive effect of the NHE on the incidence and severity of hamstring injuries in male amateur soccer players.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Male amateur soccer players (age, mean ± SD, 24.5 ± 3.8 years) from 40 teams were randomly allocated to an intervention (n = 20 teams, 292 players) or control group (n = 20 teams, 287 players). The intervention group was instructed to perform 25 sessions of NHE in a 13-week period. Both the intervention and control groups performed regular soccer training and were followed for hamstring injury incidence and severity during the 2013 calendar year. At baseline, personal characteristics (eg, age, injury history, field position) were gathered from all participants via a questionnaire. Primary outcome was injury incidence. Secondary outcomes were injury severity and compliance with the intervention protocol.

RESULTS

A total of 38 hamstring injuries were recorded, affecting 36 of 579 players (6.2%). The overall injury incidence rate was 0.7 (95% CI, 0.6-0.8) per 1000 player hours, 0.33 (95% CI, 0.25-0.46) in training, and 1.2 (95% CI, 0.82-1.94) in matches. Injury incidence rates were significantly different between the intervention (0.25; 95% CI, 0.19-0.35) and control groups (0.8; 95% CI, 0.61-1.15), χ(2)(1, n = 579) = 7.865; P = .005. The risk for hamstring injuries was reduced in the intervention group compared with the control group (odds ratio, 0.282; 95% CI, 0.110-0.721) and was statistically significant (P = .005). No statistically significant differences were identified between the intervention and control groups regarding injury severity. Compliance with the intervention protocol was 91%.

CONCLUSION

Incorporating the NHE protocol in regular amateur training significantly reduces hamstring injury incidence, but it does not reduce hamstring injury severity. Compliance with the intervention was excellent.