Prevalence and severity of groin problems in Spanish football: A prospective study beyond the time-loss approach

The time-loss definition of injury is commonly adopted in epidemiological groin-injury studies in football, with a significant risk of underestimating the impact of these injuries. This study investigated the extent of groin problems, beyond the time-loss approach, over a full Spanish football season. Players from 17 amateur male teams were followed over 39 consecutive weeks. Groin-injury time loss and self-reported groin pain, irrespective of time loss, were combined to calculate the average weekly prevalence of all groin problems with or without time loss. A subscale measuring hip- and groin-related sporting function from the Copenhagen Hip and Groin Outcome Score questionnaire (HAGOS, Sport/Rec) was registered every 4 weeks. In total, 407 players participated in the study. The average (range) weekly prevalence of all groin problems was 11.7% (7.2%-20.8%); 1.3% with time loss (0.0%-3.2%) and 10.4% without time loss (6.3%-17.6%). Players with groin problems reported lower scores (mean difference) on the HAGOS, Sport/Rec subscale compared with players without (−19.5 [95% CI: −20.7 to −18.4]), while there was no difference between players reporting groin problems with and without time loss (4.0 [95% CI: −1.1 to 9.1]). The traditional time-loss measure only captured 10% of all groin problems. Hip- and groin-related sporting function was not different between players reporting groin problems with or without time loss, suggesting the reason for continuing to play is not only related to the severity of symptoms. These findings question the judicious use of the time-loss approach in overuse conditions, such as groin pain in footballers.     

Exercise program for prevention of groin pain in football players: a cluster‐randomized trial

Groin injuries cause major problems in sports and particularly in football. Exercise is effective in treating adductor‐related groin pain, but no trials have been published regarding the specific prevention of groin pain or prevention specifically targeting overuse injuries in sport using exercise programs. We performed a cluster‐randomized trial including 55 football clubs representing 1211 players. The clubs were randomized to an exercise program aimed at preventing groin injuries (n=27) or to a control group training as usual (n=28). The intervention program consisted of six exercises including strengthening (concentric and eccentric), coordination, and core stability exercises for the muscles related to the pelvis. Physiotherapists assigned to each club registered all groin injuries. Twenty‐two clubs in each group completed the study, represented by 977 players. There was no significant effect of the intervention (HR=0.69, 95% CI 0.40–1.19). The risk of a groin injury was reduced by 31%, but this reduction was not significant. A univariate analysis showed that having had a previous groin injury almost doubles the risk of developing a new groin injury and playing at a higher level almost triples the risk of developing a groin injury.     

Inter-examiner reliability of the Doha agreement meeting classification system of groin pain in male athletes

The Doha agreement classification is used to classify groin pain in athletes. We evaluated the inter-examiner reliability of this classification system. We prospectively recruited 48 male athletes (66 symptomatic sides) with groin pain between 10–2017 and 03–2020 at a sports medicine hospital in Qatar. Two examiners (23 and 10 years of clinical experience) performed history taking, and a standardized clinical examination blinded to each other's findings. Examiners classified groin pain using the Doha agreement terminology (adductor-, inguinal-, iliopsoas-, pubic-, hip-related groin pain, or other causes of groin pain). Multiple entities were ranked in order of perceived clinical importance. Each side was classified separately for bilateral groin pain. Inter-examiner reliability was calculated using Cohen's Kappa statistic (κ). Inter-examiner reliability was slight to moderate for adductor- (κ = 0.40), inguinal- (κ = 0.44), iliopsoas- (κ = 0.57), and pubic-related groin pain (κ = 0.12), substantial for hip-related groin pain (κ = 0.62), and slight for “other causes of groin pain” (κ = 0.13). Ranking entities in order of perceived clinical importance improved inter-examiner reliability for adductor-, inguinal-, and iliopsoas-related groin pain (κ = 0.52–0.65), but not for pubic (κ = 0.12), hip (κ = 0.51), and “other causes of groin pain” (κ = 0.03). For participants with unilateral groin pain classified with a single entity (n = 7), there was 100% agreement between the two examiners. Inter-examiner reliability of the Doha agreement meeting classification system varied from slight to substantial, depending on the clinical entity. Agreement between examiners was perfect when athletes were classified with a single clinical entity of groin pain, but lower when athletes were classified with multiple clinical entities.     

Hip and groin function and strength in male ice hockey players with and without hip and groin problems in the previous season- a prospective cohort study

ObjectiveTo describe and compare hip and groin strength and function of male ice hockey players over one season in players with and without hip and groin problems in the previous season.DesignProspective cohort study.SettingSwedish male ice hockey.ParticipantsWe followed 193 players from 10 teams during the 2017/2018 season.Main outcome measuresHip adduction and abduction strength, 5 s squeeze test (5SST), and self-reported hip and groin function (Hip and Groin Outcome Score). Changes over the season and differences between players with and without problems in the previous season were analyzed by linear mixed models.ResultsAdduction strength decreased slightly from pre-to mid-season and abduction strength increased slightly over the full season. However, self-reported function or pain did not change. Players with hip and groin problems in the previous season had significantly worse self-reported function, and more groin pain during the 5SST compared to players without. Strength measurments did not differ between groups.ConclusionsHip muscle strength, groin pain, and self-reported function appear to remain stable throughout the season in male ice hockey players. Remaining impairments in players with problems in the previous season suggest that function does not recover by ice hockey participation alone.     

Running biomechanics in football players with and without hip and groin pain. A cross-sectional analysis of 116 sub-elite players

ObjectiveExamine whether football players with hip and/or groin (hip/groin) pain have impaired running biomechanics when compared to pain-free players, analysing men and women independently.DesignCross-sectional.SettingBiomechanics laboratory.ParticipantsSeventy-eight (62 men, 16 women) football players with >6months of hip/groin pain and a positive flexion-adduction-internal rotation test and 38 (25 men, 13 women) asymptomatic players.Main outcome measuresPelvis angles and hip, knee, and ankle joint angles and moments were analysed during the stance phase of overground running at 3–3.5 m⋅s⁻¹. Continuous joint angle and moment data were compared between symptomatic and asymptomatic football players of the same sex using statistical parametric mapping. Joint moment impulses (area under the curve) were compared between groups using linear regression models.ResultsSymptomatic football players did not display significant differences in pelvis angles or lower-limb joint angles, moments, or moment impulses during the stance phase of running, when compared to asymptomatic players of the same sex.ConclusionOur large sample of football players with hip/groin pain who were still participating in competitive sport displayed similar running biomechanics to asymptomatic players. Impaired running biomechanics might exist in people with worse hip/groin pain, warranting future investigation.     

Implementation of the Adductor Strengthening Programme: Players primed for adoption but reluctant to maintain — A cross‐sectional study

Groin injuries represent a considerable problem in male football, accounting for 4%‐19% of all time‐loss injuries. The Adductor Strengthening Programme is the first groin‐specific prevention program shown to reduce the risk of groin problems. We aimed to use the RE‐AIM framework to examine the players’ experiences with the implementation of the program and player attitude toward groin injury prevention in football. Of the 632 players involved in the trial examining the effect of the Adductor Strengthening Programme, 501 agreed to participate in a survey at the end of the season. Most players thought that footballers are at moderate to high risk for groin injuries (87%) and that there is a need for preventive measures (96%). They also believed that a preventive program with strengthening exercises would reduce the risk of groin injuries (91%). Majority of the players reported using <5 minutes to complete the program (73%), and only 11% wanted additional exercises. However, only 46% reported to have performed the program as recommended, and an even smaller proportion (31%) planned to continue using it as recommended the next season. Our results suggest that footballers believe that prevention of groin injuries is needed. Attitude toward implementation of the Adductor Strengthening Programme was positive, and the single‐exercise approach was considered an important facilitator. However, in future dissemination of the program, the players’ reluctance to maintain the exercise protocol may be a potential barrier to implementation that should be addressed.     

Characteristics of acute groin injuries in the hip flexor muscles — a detailed MRI study in athletes

Hip flexor injuries account for one‐third of acute groin injuries; however, little is known about specific injury characteristics. The aims of this study were to describe acute hip flexor injuries using magnetic resonance imaging (MRI ) in athletes with acute groin pain and to compare specific muscle injuries with reported injury situations. Male athletes with acute groin pain were prospectively and consecutively included during three sports seasons. MRI was performed within 7 days of injury using a standardized protocol and a reliable assessment approach. All athletes with an MRI confirmed acute hip flexor muscle injury were included. A total of 156 athletes presented with acute groin pain of which 33 athletes were included, median age 26 years (range 18‐35). There were 16 rectus femoris, 12 iliacus, 7 psoas major, 4 sartorius, and 1 tensor fascia latae injury. Rectus femoris injuries primarily occurred during kicking (10) and sprinting (4), whereas iliacus injuries most frequently occurred during change of direction (5). In 10 (63%) rectus femoris injuries, tendinous injury was observed. The iliacus and psoas major injuries were mainly observed at the musculotendinous junction (MTJ ), and two included tendinous injury. We have illustrated specific injury locations within these muscles, which may be relevant for the clinical diagnosis and prognosis of these injuries. Most proximal rectus femoris injuries included tendinous injury. In contrast, distinct acute iliacus and psoas injuries predominantly occurred at the MTJ . Only the iliacus or psoas major were injured during change of direction, whereas rectus femoris injuries occurred primarily during kicking and sprinting.     

Intrinsic risk factors for acute knee injuries among male football players: a prospective cohort study

This prospective cohort study was conducted to identify the risk factors for acute knee injuries among male football players. A total of 508 players representing 31 amateur teams were tested during the 2004 preseason for potential risk factors for knee injury through a questionnaire on previous injury, Knee Osteoarthritis Outcome Score (KOOS) and a clinical examination. Generalized estimating equations were used in univariate analyses to identify candidate risk factors, and factors with a P-value <0.10 were then examined in a multivariate model. During the football season, 61 acute knee injuries, affecting 57 legs (53 players), were registered. Univariate analyses revealed the KOOS subscores "Pain" and "Function in daily living" (OR for a 10-point difference in score: 1.26, 95% CI 1.03-1.55 and 1.35, 95% CI 0.98-1.85, respectively), any findings at clinical examination (OR: 2.62, 95% CI 1.03-6.68), flexion contraction in range of motion testing (OR: 0.96, 95% CI 0.93-1.00) and varus stress tests in full extension (OR: 8.50, 95% CI 1.85-39.0) and 30° flexion (OR: 5.69, 95% CI 1.73-18.8) as candidate factors. However, in a multivariate analysis, none of these factors were associated with an increased injury risk.     

Acute hamstring injuries in Danish elite football: A 12‐month prospective registration study among 374 players

The purpose of the present study was to examine the incidence rates of acute hamstring injuries in Danish elite football sustained during training or match play. Furthermore, it was our intention to document details about the recurrence, severity and the injury seasonal distribution. Hamstring injuries among 374 elite football players were registered prospectively during a 12‐month period. A total of 46 first‐time and eight recurrent hamstring injuries were registered. The incidence rates for incurring a first‐time hamstring injury showed a significantly (P<0.01) greater incidence rate per 1000 h during match play compared with training. Of 32 players who reported a hamstring injury in the 12‐month period before the study, eight (25%) incurred an injury that fulfilled the criteria for a recurrent injury. In 69% of the injuries, the severity of injury was categorized as moderate (8–28 days from injury to injury free) and 18% as severe (>28 days from injury to injury free). Each team sustained a mean of 3.4 hamstring injuries per season, with a mean of 21.5 days missed per injury (range 3–136; median 16 days per injury). The seasonal distribution showed an accumulation of injuries in the first 2 months after a 3.5‐month mid‐season winter break.     

Longitudinal development of match‐running performance in elite male youth soccer players

This study longitudinally examined age‐related changes in the match‐running performance of retained and released elite youth soccer players aged 8–18 years. The effect of playing position on age‐related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1–29 competitive matches (988 player‐matches). For each player‐match, total distance and distances covered at age group‐specific speed zones (low‐speed, high‐speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match‐running performance developed nonlinearly, with age‐related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age‐related changes (P < 0.05) and retained players covered significantly more low‐speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match‐running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low‐speed distance than released players, further study of the actions comprising low‐speed distance during match play is warranted to better understand factors differentiating retained and released players.     

A comparison of injuries in elite male and female football players: A five‐season prospective study

The aim was to compare the epidemiology of injuries between elite male and female football players from the same club. Injuries and individual exposure time in a male team and a female team, both playing in the Spanish first division, were prospectively recorded by the club's medical staff for five seasons (2010‐2015) following the FIFA consensus statement. Total, training, and match exposure hours per player‐season were 20% higher for men compared to women (P< .01). Total, training, and match injury incidence were 30%‐40% higher in men (P≤ .04) mainly due to a 4.82 (95% confidence interval [CI ] 2.30‐10.08) times higher incidence of contusions, as there were no differences in the incidence of muscle and joint/ligament injuries (P≥ .44). The total number of absence days was 21% larger in women owing to a 5.36 (95% CI 1.11‐25.79) times higher incidence of severe knee and ankle ligament injuries. Hamstring strains and pubalgia cases were 1.93 (95% CI 1.16‐3.20) and 11.10 (95% CI 1.48‐83.44) times more frequent in men, respectively; whereas quadriceps strains, anterior cruciate ligament ruptures, and ankle syndesmosis injuries were 2.25 (95% CI 1.22‐4.17), 4.59 (95% CI 0.93‐22.76), and 5.36 (95% CI 1.11‐25.79) times more common in women, respectively. In conclusion, prevention strategies should be tailored to the needs of male and female football players, with men more predisposed to hamstring strains and hip/groin injuries, and women to quadriceps strains and severe knee and ankle ligament injuries.     

In‐season adaptations to intense intermittent training and sprint interval training in sub‐elite football players

This study investigated the in‐season effect of intensified training comparing the efficacy of duration‐matched intense intermittent exercise training with sprint interval training in increasing intermittent running performance, sprint ability, and muscle content of proteins related to ion handling and metabolism in football players. After the first two weeks in the season, 22 sub‐elite football players completed either 10 weeks of intense intermittent training using the 10‐20‐30 training concept (10‐20‐30, n = 12) or sprint interval training (SIT, n = 10; work/rest ratio: 6‐s/54‐s) three times weekly, with a ~20% reduction in weekly training time. Before and after the intervention, players performed a Yo‐Yo intermittent recovery test level 1 (Yo‐Yo IR1) and a 30‐m sprint test. Furthermore, players had a muscle biopsy taken from the vastus lateralis. Yo‐Yo IR1 performance increased by 330 m (95%CI: 178‐482, P ≤ 0.01) in 10‐20‐30, whereas no change was observed in SIT. Sprint time did not change in 10‐20‐30 but decreased by 0.04 second (95%CI: 0.00‐0.09, P ≤ 0.05) in SIT. Muscle content of HADHA (24%, P ≤ 0.01), PDH‐E1α (40%, P ≤ 0.01), complex I‐V of the electron transport chain (ETC) (51%, P ≤ 0.01) and Na⁺, K⁺‐ATPase subunits α₂ (33%, P ≤ 0.05) and β₁ (27%, P ≤ 0.05) increased in 10‐20‐30, whereas content of DHPR (27%, P ≤ 0.01) and complex I‐V of the ETC (31%, P ≤ 0.05) increased in SIT. Intense intermittent training, combining short sprints and a high aerobic load, is superior to regular sprint interval training in increasing intense intermittent running performance during a Yo‐Yo IR1 test and muscle content of PDH‐E1α and HADHA in sub‐elite football players.     

Achilles tendon structure improves on UTC imaging over a 5‐month pre‐season in elite Australian football players

Pre‐season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre‐season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5‐month pre‐season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5‐month pre‐season. Fifteen players remained asymptomatic over the course of the pre‐season. All four echo‐types were significantly different at the end of the pre‐season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5‐month pre‐season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity.     

Hip passive range of motion and frequency of radiographic hip osteoarthritis in former elite handball players

Objective

To establish the relation between handball playing, passive hip range of motion (ROM), and the development of radiological hip osteoarthritis (OA) in former elite handball players. Two related issues are addressed: (a) the relation between long term elite handball playing and the incidence of hip OA; (b) the relations between hip ROM, OA, and pain.

Methods

Data on 20 former elite handball players and 39 control subjects were collected. A questionnaire yielded personal details, loading patterns during physical activity, and previous lower limb joint injury. Bilateral radiographs were analysed to diagnose and classify hip OA. Passive hip ROM was measured bilaterally with a goniometer.

Results

A close relation was found between long term elite handball practice and the incidence of hip OA: 60% of the handball players were diagnosed with OA in at least one of the hip joints compared with 13% of the control subjects. Passive ROM measured in the handball players was significantly lower for hip flexion and medial rotation and higher for abduction, extension, and lateral rotation than the control values. The handball players with OA reported less pain in the hip joints during daily activities than the control subjects with OA.

Conclusion

The risk of developing premature hip OA seems high for retired handball players and significantly greater than for the general population. Pain and discomfort represent two difficult diagnostic challenges to the sports physician, as the repetitive nature of movements that are specific to handball can lead to alterations that are rarely seen in the general population.     

Field-based evaluation of hip adductor and abductor strength in professional male ice hockey players: Reference values and influencing factors

ObjectivesTo provide reference values and examine the influence of hip/groin pain on hip adductor and abductor strength in professional male ice hockey players, by using a straightforward 5-min procedure.DesignCross-sectional study.SettingOn-field assessment of hip/groin muscle strength with dynamometry, together with the concomitant level of hip/groin pain with a visual analogue scale.ParticipantsProfessional male ice hockey players competing in the Swiss National League (n = 187).Main outcome measuresHip abductor strength, hip adductor strength and hip adductor:abductor ratio.ResultsReference values by playing position (goalkeepers, defenders and forwards) are provided for asymptomatic athletes. Players with hip/groin pain during adduction displayed lower hip adductor strength (p = 0.001) and hip adductor:abductor ratio (p = 0.012) than their symptom-free peers.ConclusionsThe presence of hip/groin pain during adductor testing may contribute to selective hip adductor weakness, whose cause-effect relation with possible groin problems remains to be demonstrated.     

Hip muscle activity in male football players with hip-related pain; a comparison with asymptomatic controls during walking

ObjectivesCompare muscle activity between male football players with and without hip-related pain. Morphological and intra-articular features of hip-related pain are proposed pre-cursors to hip osteoarthritis. Altered muscle activity is a feature of severe hip osteoarthritis, but it is not known whether differences exist earlier in the pathological spectrum.DesignCross-sectional;SettingUniversity laboratory;ParticipantsForty-two male football players with hip-related pain; and 19 asymptomatic controls.Main outcome measuresHip muscle activity (Gluteus maximus, gluteus medius, tensor facia latae, adductor longus and rectus femoris) was recorded during walking using surface electromyography (EMG).ResultsMen with hip-related pain had sustained rectus femoris activity prior to toe-off (47–51% of the gait cycle) (p = 0.01, ES = 0.51) unlike controls who had reduced activity. In men with severe hip-related pain, gluteus maximus EMG was sustained into mid-stance (12–20% of the gait cycle) (F = 6.15, p < 0.01) compared to controls.ConclusionsDifferences in rectus femoris and gluteus maximus activity were identified between male footballers with and without hip-related pain. The pattern of gluteus maximus EMG relative to peak, approaching mid-stance in severe hip-related pain, is consistent with observations in severe hip osteoarthritis. This supports the hypothesis that symptom severity may influence muscle activity across the spectrum of hip degeneration.     

Incidence,burden, and pattern of injuries in Spanish male youth soccer players: A prospective cohort study

ObjectivesTo explore the incidence, burden, and pattern of injuries in Spanish male youth soccer players during a 9-month competitive season (from September to May–June).DesignProspective cohort study.Participants314 young (10–19 years) soccer players.Main outcome measuresIncidence, burden, location, type, severity, mechanism, and circumstance of injuries, as well as potential differences by tactical position, month of the year, age group, and maturity status.ResultsA total of 146 time-loss injuries were sustained by 101 different players. This resulted in an overall injury incidence of 3.1 injuries per 1000 h, a training injury incidence of 1.8 injuries per 1000 h, and a match injury incidence of 11.2 injuries per 1000 h. The probability of injury over the season was 34%. Most of the injuries affected the lower extremity and were classified as muscle/tendon injuries, with hamstring muscle injuries representing the most burdensome diagnosis. The incidence of injuries increased with age and maturation, but a heightened risk of overuse injuries during periods around peak height velocity was also identified.ConclusionsThese findings suggest a need for implementing specific injury prevention measures. Due to the high burden shown, these measures should mainly focus on reducing the number and severity of hamstring muscle injuries.     

Effects of hamstring‐emphasized neuromuscular training on strength and sprinting mechanics in football players

The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty‐seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7‐week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5‐m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = ?0.02/0.11). Thus, in contrast to the CG (ES = ?0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = ?0.35/?0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players.