Injury Prevention and Rehabilitation in Sport E-Book

Ross Bennett

• Herausgeber: Crowood
• Kategorie: Bildung
• Sprache: Englisch

Veröffentlichungsjahr: 2015

Beschreibung

Injury Prevention and Rehabilitation in Sport examines the key factors at play in the reduction and prevention of injury to athletes at all levels of sport. The book combines the latest scientific research with a critical review of current literature and the author's own personal experience working in the field of strength and conditioning at elite level to explain why certain modalities should or should not be prescribed by strength and conditioning coaches. There are full colour sequenced photographs showing the correct techniques for a wide variety of essential strength exercises. Other topics covered include how to effectively manage recovery and avoid overtraining; techniques for range of movement and corrective exercise; the most effective methods for shoulder and trunk stability; the theory and practice of propioception and plyometrics and how they can improve performance; the different methods employed when working with female or maturing athletes and the physiological impact of factors such as sleep patterns, travel, climate and illness on performance. The book concludes with a series of case studies that illustrate how to put theory into practice. Fully illustrated with 110 colour sequenced photographs and diagrams.

Leseprobe

Injury Prevention and Rehabilitation in Sport

Ross Bennett

THE CROWOOD PRESS

First published in 2015 by

The Crowood Press Ltd

Ramsbury, Marlborough

Wiltshire SN8 2HR

www.crowood.com

This e-book first published in 2015

© Ross Bennett 2015

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publishers.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

ISBN 978 1 84797 958 2

Disclaimer

The author and publishers of this book do not accept any responsibility whatsoever for any error or omission, nor any loss, injury, damage, adverse outcome or liability suffered as a result of the use of the information contained in this book, or reliance upon it. Since some of the training exercises can be dangerous and could involve physical activities that are too strenuous for some individuals to engage in safely, it is essential that a doctor be consulted before training is undertaken.

Acknowledgements

I would like to say a huge thank-you to my wife Lucia and all my family for their continued support for my career so far. I would also like to acknowledge all lecturers and work colleagues who have contributed to my learning over the years, and have helped me mould a personal philosophy within strength and conditioning/sports science. I hope you all enjoy the book.

CONTENTS

About the Author

Introduction

1

THE IMPORTANCE OF MAXIMAL STRENGTH

2

MANAGING RECOVERY AND AVOIDING OVERTRAINING

3

RANGE OF MOVEMENT AND CORRECTIVE EXERCISE

4

A FOCUS ON SHOULDER STABILITY

5

TRUNK STABILITY

6

PROPRIOCEPTION AND PLYOMETRIC PERFORMANCE

7

THE FEMALE ATHLETE

8

MATURING AND YOUTH ATHLETES

9

THE PHYSIOLOGY MODULE

10

REHAB FROM AN S&C PERSPECTIVE

11

APPLIED CASE STUDY: PUTTING THEORY INTO PRACTICE

References

Index

ABOUT THE AUTHOR

Ross Bennett was originally an aspiring football player registered with a number of Premier League football clubs as a youth team player but after injury and lack of progression he decided to enter the academic world. In 2008 he enrolled on the BSc Strength and Conditioning Sciences degree programme at St Mary’s University, Twickenham. While in his second year Ross was offered a part-time internship at Chelsea FC Academy and was subsequently offered a part-time role at the club.

He spent four years at Chelsea, during which time he completed an MSc in Human Performance (Sports Science) at Brunel University. Both his dissertation research papers won best research poster at the annual UKSCA conference two years in a row (2011 and 2012).

Following a brief spell at the Aspire Centre in Qatar working with one of the national teams, he returned to the UK and currently heads the Strength and Conditioning team at Queens Park Rangers FC Academy.

INTRODUCTION

This current textbook outlines and discusses key areas that are essential for the reduction of injury when working with athletes on a daily basis or part time, depending on the level and age of the athlete. It will look at varying aspects and ideas in isolation to reduce injury rates, as well as providing ongoing personal philosophies of mine, which will run throughout the chapters. Although increasing performance isn’t the priority of this current textbook, it will become apparent that the two often go hand in hand, with either a direct stimulus to both, or providing a stable base for performance enhancement, while having the underlying aim of reducing potential for injury.

The book’s content combines scientific research findings, critical review of the current literature, and my personal experience working in the field of strength and conditioning at elite level. Some areas will have a greater focus on research; others that lack direct research will adopt an approach based on ideas that I have assimilated as a practising strength and conditioning coach. It must be noted, however, that although other concepts may be based on my current experience in the field, I do not claim to be the sole inventor of these techniques; instead my practice frequently involves generic modalities that have been implemented by many practitioners previously. The aim of this textbook is to provide a structure in which the reasons why these modalities should or should not be prescribed are discussed. Furthermore, to summarize and tie together all the injury prevention techniques, a diagrammatic structure is given at the end of Chapter 9 to link all the modalities together, highlighting their importance in injury prevention.

The rehabilitation section (Chapter 10) explores techniques available to the practitioner when an athlete is immobile and during recovery and rehab. It is not my intention to tread on the toes of the physiotherapists or sports therapists in clinical injury prevention: some interesting tips are given on how to assist the work of the therapist and possibly bridge the gap between rehab and fully functional sports training without restriction.

1

THE IMPORTANCE OF MAXIMAL STRENGTH

I t is an often neglected consideration in strength and conditioning that a well-constructed strength programme can act as a key factor in injury prevention as well as a tool for performance enhancement. Increasing the strength of key musculature and connective structures causes an increase in their integrity and robustness. This in turn enables larger acute forces or greater volume and an increasing training stimulus to be applied without a potential breakdown. Furthermore, depending on the anatomical region of strength increase, this will elicit injury prevention benefits by increasing the stability of a joint. For example, strengthening the hamstrings will directly result in increased stability of the knee joint, thus illustrating the important role the hamstrings play in stabilizing the knee (Olsen et al., 2005). Therefore, stronger hamstrings in particular will in turn reduce direct hamstring injuries such as tears, and consequently knee injuries, especially reducing injuries involved in rotation of the knee. (The importance of posterior chain strength and benefits will be explained in greater detail in a later section of this chapter.)

It may seem that this chapter is placed out of order in injury prevention programme design, as there are essential components of reducing injury that might be prescribed prior to strength training. For example, an athlete’s ROM (range of movement) and stability around particular joints could be a focus prior to heavier strength training, and a later chapter within this book will specifically discuss the importance of corrective exercise to the athlete. However, this chapter was selected to appear first, as I believe (particularly in the sport in which I work – football) maximal strength is often neglected and misunderstood, including the benefits it can have in reducing injury rates.

Many practitioners within the field of strength and conditioning are over-cautious when applying strength training programmes to athletes, either because they are concerned for their safety, or they are worried that it might create a physiological adaptation of hypertrophy that is deemed detrimental to athletic performance. To combat this, a strength development programme is given in this chapter, which enables a modified long-term athletic development (LTAD) programme to ensure a safe and steady progression to increased strength. Guidelines are given in this chapter to create strength adaptation without necessarily causing an increase in any unwanted hypertrophy.

A progression/continuum for strength development is given below. Note that coaches and sports scientists will not always have access to athletes as young as nine, so the following steps can be applied and adapted to athletes at any age. LTAD is examined in much greater detail in Chapter 8 (Maturing and Youth Athletes).

STAGE 1 (AGE 9–12): INTRODUCTION TO FUNDAMENTAL MOVEMENT PATTERNS

Create mobility drills that will ensure an athlete is able to generate full ROM. Body weight exercises are essential; ensure that movement occurs with no dysfunction or compensation. If you have access to players at this age group, then this stage is essential and conforms to the high flexibility and ROM an athlete has at this age (this naturally decreases as chronological age increases). The aim is to provide a wide range of exercises, to broaden an athlete’s skills set and to challenge them from a motor skill development point of view.

STAGE 2 (AGE 13–14): INCREASING MOTOR CONTROL

Still prescribing a combination of bodyweight and loaded exercises, exercise prescription should be restricted to those that will be more essential for functional strength development, although variation at times is essential for psychological/physiological benefit. A list of key exercises and the benefit of each one will also be included in this section. We can now start to increase the intensity and volume a bit more, but ensure the movement is under good control. Take extra care when working with this age group: as they go through greatest peak height velocity phases (growth spurt) some athletes can experience movement issues or difficulties. This phase should also start to look at individuals who need specific ROM or stability work. Commonly, supplementary glute strength and ankle ROM training is required to enhance movement quality.

STAGE 3 (AGE 15–16): HIGH VOLUME LOAD TIME (WORK CAPACITY STRENGTH)

After previous technical phases and motor control work, it’s time to increase the intensity in the gym. Based on previous experience, keeping volume relatively high post growth spurt and gradually increasing intensity seems to bridge the gap between motor control phases and general maximal strength work. Remember: if the load is higher than what the athlete is used to or has lifted before, an overload is created, which is essential for adaptation. If you are fortunate enough to be working with your athletes from a younger age, at this stage of their development there is often a natural increase in circulating hormones such as testosterone to assist further neurological gains and is thus an appropriate time to apply strength work. However, all athletes develop and mature at different times, and some may still have late growth issues as they go though PHV phases. Athletes go through their optimal strength/weight gaining phase approximately 18 months after PHV. It is therefore the responsibility of the coach and practitioner to assess the appropriate timing for the implementation of this phase.

STAGE 4 (AGE 17+): TRADITIONAL MAXIMAL STRENGTH PHASE

After the three previous phases, your athlete should now be technically and physically competent, and can be prescribed a well-constructed traditional periodized strength programme to maximize their strength over a period of time. A guide to recommended repetitions is given; there will also be a section on periodization later in this textbook to demonstrate the importance of volume and intensity and how it should be fluctuated.

It is essential to note that if you are working with an athlete that you haven’t had from a young age, the stage length does not have to be exactly as suggested above, where the ages are given in brackets. It is up to the coach to determine when the athlete should move into the next phase. Moreover, players develop at a vast range of different rates: the age ranges are given merely as a guide.

The table provides recommendations within each phase of strength development; it provides a guideline based on my experience and scientific research (see for example Baechle and Earle, 2000; Siff, 2003). Certain variables must be adjusted for individuals, taking into account other forms of training load they are undertaking. For example, you may have a scheduled work capacity phase and session to do with a particular athlete or team. An aspect to consider within this framework is the differences between certain athletes, as some will be able to tolerate more load than others. Although we need to hit a certain threshold for adaptation, that threshold will depend on each athlete individually. Identifying this threshold is an important skill in its own right for a coach/practitioner to develop, to know your athlete well and what should be prescribed for them in order to get the balance right for getting your athletes stronger and more robust, but not acutely causing them to break down. The idea is to apply the minimal dose possible for adaptation, although over reaching techniques are required at times. Again, this depends upon a particular athlete’s genetic make-up and potential, in what is known in the scientific research as being a responder or non-responder to various stimuli (Davidsen et al., 2011). Unfortunately, the genetic make-up of athletes is out of anyone’s control, so it is once again up to the coach to ensure that maximum adaptation can be made with their athletes. Another thing to consider is the workload and schedule the athletes are going through beyond the strength and conditioning (S&C) programme. It may be that the S&C does not cause any injury concerns, but the overall load may contribute to overload injuries.

Strength development phase

Recommended sets

Recommended repetitions

Recommended recovery time

Fundamental movement patterns

Incorporate in games or warm-up drills

8–12

n/a

Motor control/intro Work capacity/high volume strength

2–4 2–5

6–12 6–10 (sub-maximal level)

30–90 seconds 15–45 seconds

Increasing maximal strength

3–6

2–5 (progressing to maximal lifts) 6–8 (functional hypertrophy)

2–4 minutes

Note that there is an extra repetition range in the strength section for functional hypertrophy, which could be used in certain aspects of the season or cycle. (Functional hypertrophy means there is an increase in muscle cross-sectional area that relates to a direct increase in force production.) My recommendation is that repetition range should never exceed this in a functional hypertrophy phase, otherwise the intensity and percentage of maximal load will have to decrease too much, eliciting a decrease in force production. It would also cause an increase in hypertrophy that is not functional, therefore producing size that would inhibit performance. In the earlier stages of strength development when motor control/work capacity is being performed, coaches do not need to worry about any unwanted hypertrophy as athletes are still learning motor skills and greater repetitions are potentially required (Stafford, 2005). However, there is definitely scope to prescribe higher repetition ranges to an athlete within an anatomical adaptation phase, or when the athlete is new to strength training. If done correctly it can also be implemented as a variation within a strength cycle to provide a two-week shock for the athlete and reduce the neurological stress. It can also complement a corrective exercise type programme, where a particular dysfunction is being fixed and then patterned into an integrated movement.

VOLUME VS. INTENSITY

There is a real debate in S&C literature and amongst practising coaches about whether a programme that is high-volume, high-intensity, or somewhere in between is the ideal prescription for optimal strength development; much depends on the coach’s personal philosophy and experience within the field. There is no doubt that the fluctuation of training load is imperative not only for strength adaptation but for recovery (Stone et al., 1999a; 1999b), although this periodized tool will be discussed in greater detail later on this textbook.

Furthermore, much depends on the type of sport, athlete and perception of high intensity/volume programmes. For example, there may be a need for greater strength volume throughout the week if strength is a greater priority in your sport. For example, a rugby player will have a number of consecutive sessions based on strength throughout the week; other team invasion sports such as football or hockey, although benefiting greatly from strength sessions, need to develop other physical qualities, so a lower volume of weekly and total strength work will therefore occur for these sports.

This book is not designed to specify how many strength sessions should be included in a particular sport or cycle phase, but instead to give careful consideration to the notion that there is more than one way of constructing and performing a well-implemented strength programme. The key exercises that follow provide an important stimulus for certain musculature and connective structures, and are necessary to optimize force production, essential for increasing strength and therefore reducing the potential for injury. Some of these exercises will be discussed in depth; others will be dealt with in general terms or listed within a key category.

Please note that although the exercises are prescribed with good scientific rationale, there will be cases where some athletes may not benefit from certain exercises at particular times, for example in a busy competition period or if an individual needs to fix dysfunctions prior to a strength programme. However, the exercises given below are recommended as tools for the majority of athletes.

THE EXERCISES

The squat

There is some disagreement amongst coaches as to how wide the stance should be. From experience, if an athlete struggles to get good depth, a wider stance can be adopted, although some tests such as the Functional Movement Screen (FMS) prohibit any stance wider than shoulder width to highlight any compensation (Cook, Burton and Hoogenboom, 2006) – in other words, if an athlete has to adopt a wider stance to get good depth in a squat, is the athlete compensating somewhere? For example, a lack of dorsiflexion within an athlete limits good depth so a wider stance would compensate and create the depth required. The coach then has to ensure that this dysfunction is addressed along with squatting work.

It is commonly believed that squats in general are bad for the knee joint, and that coaches should prevent athletes from allowing their knees to go over their toes. Although as coaches we should try to enforce the posterior tilt of the pelvis so the weight distribution goes through the heels, ensuring a greater activation of the posterior chain, there is no scientific evidence to support that knees going over the toes is detrimental to knee health. In fact, contrasting research demonstrates that squatting does not exert high forces on the knee, or place the anterior cruciate ligament (ACL) under much strain (Escamilla, 2001). In fact, greater dorsiflexion ability within the squat would enable better movement and less compensation at other joints so ensuring the knees go over the toes as much as possible will enhance ankle mobility.

What is very well-known and conclusive, however, is the depth required when performing the squat exercise. If an athlete reaches a depth of the legs where they are parallel to the floor or deeper, there is a greater shift of activation to the gluteus groups of muscles (Caterisano et al., 2002), also known as the posterior chain of the lower limb, but not so much for the hamstrings (Isear, Erickson and Worrel, 1997). Since more or less all of the sports are quadriceps-dominant, due to the repetitive smaller ranges of movement of the hip and knee joint required to perform the sporting activities, it is essential that this exercise elicits a greater stimulus to the posterior chain in an attempt to balance the strength levels in the lower limb. Alongside deep squatting exercises, athletes need to be performing specific hamstring exercises; these will be discussed further in the next section. As briefly discussed in the introduction to strength training, note that for a reduction in knee injuries, the posterior chain in particular should be strengthened for greater control and stability at the hip and knee joints.

Significant performance benefits can be gained with squats that are partial in depth, as the specificity of force production is greater than sporting movement itself. However, with partial squatting, the dominant muscles required for the movement are the quadriceps, which counteract the balancing operation of the lower limb. There is rationale at certain phases of the cycle/season, however, for implementing high force partial squats, as the load being lifted would be significantly greater, causing neurological overload, as there will be an optimal length tension relation for generating high levels of force (Hill, 1953; Huxley, 1957). The majority of the training prescription should be reinforcing good depth of a squat, from an injury prevention point of view. As mentioned above, the gluteus group of muscles can be targeted within deep squatting exercises; the coach also needs to elicit techniques that strengthen the hamstring group of muscles for an effective injury prevention programme.

Back and front squat exercises, with full ROM for enhancing triple extension strength of the lower limb.

Although for a healthy athlete with good mobility the squat exercise is an extremely effective exercise to use, it must be noted that it isn’t always the best exercise to use with some athletes. For example, if an athlete has poor ankle mobility, then they will search for more depth with compensation at other joints. Therefore, squatting may not be in their programme and enhancing ankle mobility will be an emphasis within their prehab programmes. With this athlete then, the leg press may be used as an alternative to a squat exercise. This will be more thoroughly discussed in the Chapter 3, and demonstrated in the applied case study; however, coaches need to provide individualized programmes.

Eccentric loading exercises

The eccentric phase of an exercise is often known as the negative or downward phase, and there are many exercises that focus on this eccentric part in particular for strengthening. It must be stated, firstly, that eccentric training focuses on applying tension to a muscle while it lengthens as opposed to when it shortens in the concentric phase. For the hamstrings in particular, exercises such as the Romanian deadlift (RDL), good morning, and Nordic exercise are examples of eccentrically loading the hamstrings. Exercises such as the RDL will enhance the hamstring strength whilst hinging from the hip when the knee joint is close to extension. The Nordic exercise is completed whilst the knee joint is flexed, so the two exercises should be completed together within a hamstring programme. Eccentric loading exercises provide a direct stimulus to improve the strength of these muscles as they are said to have greater strength responses than concentric training alone (Roig et al., 2009), and reduce injury rates within athletes (Croisier et al., 2008: Olsen et al., 2005). Exercises such as the Nordic hamstring exercise can be implemented with very young and novice athletes; providing athletes can control their own bodyweight under eccentric load, they will be a thorough starting point for the progression of eccentric loading. In my experience, exercises that concentrically activate the hamstrings, such as leg curls, should be avoided, as lengthening the hamstrings is essential for injury prevention. Eccentric training can also be applied to all exercises as the lengthening/downward phase can be emphasized. A spotter is required, though, as the athlete should be able to eccentrically control up to approximately 120 per cent of their concentric one repetition max (1RM) (Roig et al., 2009), with assistance on the concentric phase to lift the load. This eccentric high load method can be utilized with many strength exercises, not just hamstring-conditioning ones.

Isometric hamstring conditioning

Although eccentric hamstring training has been endorsed and encouraged in most recent years for reducing hamstring injuries, there is a small argument against it. When hamstring injuries occur generally, it does so when the hamstrings are in a brief isometric state close to full extension of the knee joint. Therefore, the practitioner is encouraged to incorporate some isometric conditioning of the hamstrings within their injury prevention programmes. Exercise such as back hyperextensions and bridges with the legs close to full extension would be examples of this.

High intensity running

As well as looking at enhancing the eccentric loading of the hamstring group of muscles, it is important that they are conditioned under higher velocity actions as well. Within many sports, the amount of maximal sprints that occurs over 30m is limited within technical/tactical training and the majority of game play. Therefore, the hamstrings are generally unconditioned over longer distances when fatigue starts to occur. It is therefore imperative that some longer distance sprinting, or close to sprinting, is placed within an athlete’s programme so they are exposed to this type of repetitive hamstring contraction. The hamstrings have to load eccentrically at a rapid rate when at the end of extension, whereas resistance exercises such as the RDL and Nordic only provide a slower eccentric contraction. The coach can build up the distance/repetitions/sets when they feel it is appropriate for that athlete/sport. Furthermore, it is essential that athletes are exposed to this type of stimuli for a reduced risk of hamstring injury.

High force producing exercises: Focus on the ‘deadlift’

As mentioned briefly earlier in this text, maximizing an athlete’s force-producing capabilities will increase the robustness and integrity of that area. Therefore, another important injury prevention tool will dedicate time to maximizing force-producing capabilities. The partial squat, which has been mentioned previously in the context of maximizing force capabilities, should be used sparingly throughout a periodized programme. However, an exercise such as the deadlift, where the bar must be lifted from the ground with good posture, can generate greater load/weight. Remember that force is equal to mass × acceleration, so lifting the most mass with the greatest speed or intention to lift fast will ensure greater force production and strength adaptation. Further, it is important to understand that maximizing force is only a part of an injury prevention programme and other modalities are essential. If attempting to maximize the force and load lifted in this exercise, the use of straps must be permitted in order to avoid a weak grip limiting force producing capabilities in the triple extension position.

Starting and finishing positions of the deadlift exercise. It is important to maintain this posture over the bar throughout the lift. Stand fully erect to complete the lift.

Starting and finishing positions for the Romanian deadlift exercise. Move the bottom back as far as possible, whilst the bar travels down the front of the legs. Keep legs as straight as possible to load the hamstrings more. As usual, posture is key: maintain the neutral spine position throughout.

Olympic lifts such as the clean-and-jerk and snatch are common weightlifting exercises used in the field of strength and conditioning. Though they provide some injury prevention benefit, they are designed to increase explosive strength and power, and therefore are used more as a performance enhancement tool. These lifts will therefore not be discussed at length within this textbook.

Upper body strength exercises

A common issue amongst certain athletes when training the upper body is an obsession with wanting to do exercises that enhance aesthetic qualities of their physique, not performance qualities. Although these ‘non-functional’ exercises (the bicep curl and chest fly, for example) could be placed in a particular athlete’s programme at some point, with good justification and rationale, it is essential that athletes are reminded that going to the gym and just performing this type of exercise will not enhance their performance. Instead, upper body exercises should be compound lifts: a push/pull in both horizontal and vertical planes. Horizontal force production includes key exercises such as the bench press and bent-over row/bench row, whilst vertical force production lifts include shoulder/push press and pull-ups. Although there are many exercises that could be implemented, these are the main four types of lift, essential for a strength programme focused around the upper body.

These exercises demonstrate the technical aspects of the two horizontal push/pull complexes – the bench press and the bent over row. It is important in the bench press that the athlete pushes through the ground to generate force and extend the arms as fast as possible. The bent over row exercise ensures the athlete gets the upper body as parallel to the floor as possible, promoting effective hinging patterns also.