Stretching in the prevention of hamstring strains: Attitudes, beliefs and current practices among football coaches in Mauritius ()
1. INTRODUCTION
Soccer, or football, as it is officially called by the “Fédération Internationale de Football Association” (FIFA), is the most popular sport in the world. Due to the nature of the game, which involves kicking, sprinting and jumping, muscle strains are common and represent 33% of all injuries reported in the English professional football clubs [1]. Hamstring strains in particular are the most common type of muscular strain to affect the lower limb in the elite football player [2].
The literature suggests insufficient warm up, poor flexibility, muscle strength imbalance, muscle weakness, neural tension, muscle fatigue, dy-synergic contraction of muscle groups, previous injury and inadequate rehabilitation of previous injury [1,3] as predisposing factors for hamstring strains. Efforts should be made to prevent hamstring strain since it is a frustrating injury for coaches and football players: the symptoms are persistent, a significant amount of matches is missed per hamstring strain and re-injury rates are high [4]. Since muscle tightness is thought to predispose athletes to strains, stretching is widely regarded as an important part of warm-up and a necessity for fitness, flexibility and injury prevention [5]. However there is conflicting evidence in the literature concerning the relationship between stretching and injury prevention. Coaches usually recommend stretching before participation in sports activities in an effort to prevent injury [6] and football coaches are no exception. However, there is a relative lack of literature on the stretching practices that occur in professional sports [1]. Therefore the purpose of this study is to determine the attitudes, beliefs and practices of football coaches regarding stretching in the prevention of hamstring strains.
2. METHODS
The study sample consisted of a random sample of 35 football coaches in Mauritius who were registered with the MFA as at December-March 2010. The final sample consisted of 26 registered football coaches. The participants coached football teams either on a full-time or part-time basis.
2.1. Survey Instrument
The survey instrument used was a self-designed questionnaire based on a review of the literature and discussion with physiotherapists and football coaches otherwise not involved in this study. The questionnaire comprised three sections. Section A inquired about personal demographic information such as gender, age, number of years of experience as a football coach, and which team/ division was being coached. Section B consisted of an attitude scale to investigate the coaches’ attitudes and beliefs towards stretching in football. A 5-point Likert scale was used, with “strongly disagree” and “strongly agree” as anchors. Ten positive and negative statements about stretching were interspersed in the scale. Finally Section C inquired about the stretching protocols used on the field, the warm-up and weekly training patterns of football clubs, which techniques were used to stretch the hamstrings and the main reason that coaches advised players to stretch. The questionnaire consisted mostly of closed-ended questions with two open-ended questions in Section C.
The first draft of the questionnaire was piloted among 5 individuals and took approximately 15 minutes to be completed. As per the recommendations received from the pilot study, some technical terms had to be illustrated with diagrams or their equivalent French terms given in brackets.
2.2. Conduct of Study
Ethical clearance was granted by the Research Ethics Committee of the University of Mauritius for the study. After initial conversations on the phone, personal meetings were arranged between the researcher and the sports officers of the MFA. The sports officers agreed to allow the football coaches to participate in the study and they distributed the questionnaires to the football coaches. The questionnaires started being collected 2 weeks after initial distribution by the researcher. The final return rate was 77%.
2.3. Procedure
The participants were given a booklet containing an information sheet, a consent form and a three-section questionnaire. The information sheet explained the aim of the study, provided definitions of key terms used throughout the questionnaire and the contact details of the researcher. Although the consent form included individual identifiers, it was explained to the sports officers that completing this part was optional.
2.4. Data Analysis
Initially response frequencies for each survey item were determined manually in tally form. Microsoft Office Excel 2007 was then used to analyse the data from the questionnaires. Where an item was left unanswered on the 5-point Likert scale, it was analysed as though a neutral response had been chosen [7]. In the other sections of the questionnaire, a valid percentage (i.e. the denominator is number of respondents to that specific question, not total number of participants in the study) was calculated wherever a question was left unanswered [8].
3. RESULTS
All the respondents were male, with an age range of 19 to 60 years old. The mean age was 46.0 ± 10.6 years. All had received formal training to become a football coach. The football coaches coached a variety of teams ranging from the National Team to the young players in so-called “Schools of Football”. Table 1 shows the proportion of coaches and their corresponding years of experience.
3.1. Attitudes and Beliefs towards Stretching
The respondents held generally positive attitudes and beliefs towards stretching. A majority replied that they agreed or strongly agreed that: stretching before training or competition is beneficial (88%) and that stretching before training or competition helps to prevent hamstring strains (93%). A majority agreed or strongly agreed that tight hamstrings are a risk factor for hamstring strains (77%) and that it is important for football players to have flexible muscles (100%), as shown in Table 2. Respondents were diverse in their opinions about the statement that there was not enough scientific proof that stretching can reduce injuries: 46% stated they disagreed or strongly
Table 1. Personal demographic information of football coaches.
disagreed, 31% stated they agreed or strongly agreed with the statement and 23% were neutral.
3.2. Perceived Benefits of Pre-Exercise Stretching
A majority of coaches replied that they agreed or strongly agreed that: pre-exercise stretching (PES) helps to prevent hamstring strains (93%), stretching acts as mental preparation for training/matches (77%) and that PES increases a player’s performance (88%).
3.3. Perceived Drawbacks of Stretching
As shown in Table 2, responses were diverse concerning whether the time taken for stretching could be better used on more useful forms of preparation: 53% stated they disagreed or strongly disagreed, 39% stated they agreed or strongly agreed with this statement and 8% were neutral. Moreover 88% of respondents disagreed or strongly disagreed that stretching is harmful and can cause muscle injury.
3.4. Training Patterns
As shown in Table 3, coaches trained their teams on average for 15.1 ± 7.5 hours per week. Coaches devoted an average of 1.3 ± 0.6 hours per week to stretching/ flexibility training. As shown in Figure 1, football coaches devoted 31% of the total weekly training time to skills/ technical training, 30% to endurance training, 12% to strength/resistance training, and 10% to speed training. The time spent on stretching/flexibility training accounted for 9% of the total weekly training time.
All the coaches reported using warm-up before training sessions and before matches. The mean time for warm-up before training was 23 ± 6 minutes and the mean time for warm-up before matches was 26 ± 8 minutes.
Figure 2 shows the time at which stretching is recommended by coaches. The majority of coaches recommended stretching after warming up (81%) and after the training session (93%). 22% reported recommending stretching before warm-up, 33% during warm-up and 26% recommended stretching at mid-session. 76% of coaches also recommended stretching outside training sessions e.g. at home.