Specific Conditioning to Reduce Injury Risk

Stuart Butler

Highlights

• • Improving the strength of a muscle or specific structure is unlikely to alter running biomechanics but may enable tissues to withstand greater volumes of loading, thereby reducing injury risk.
• • Conditioning exercises should be prescribed with a specific adaptation in mind that considers the primary function of biological tissues that are injured or vulnerable to injury.
• • For the injured runner, conditioning programmes should aim to load the athlete using alternative ‘off feet’ methods and re-condition the injured tissues for a successful return to running training.
• • Running drills, low-level plyometrics and mobility exercises (e.g. hurdle walkovers) should form an important part of a runner’s conditioning routine and can be incorporated into pre-session warm-up routines.
• • Targeted conditioning exercises should aim to develop the capacity and strength of structures around the foot and ankle, knee, hip and trunk using a volume-driven approach initially that progressively increases in intensity (load) over time.

Introduction

Prevention is said to be better than cure; however, the skill and art of running and load management within a technical framework are complex. Injury prevention is the panacea, but it may be better to view injury avoidance as a ‘risk management strategy’, with athletes and coaches agreeing on a shared plan to manage the risk. Based upon an initial screening and assessment of load capacity (see Chapter 7), a priority list of objectives and goals should be agreed within a training cycle/race plan. Identifying ‘must do’s’, ‘should do’s’ and ‘could do’s’ provides a simple system to organise a program at any given time based upon the results of screening and an athlete’s injury history. It is also worth considering what an athlete would do if they are unable to run for a period of time, i.e. a list of areas that could be developed if the opportunity arises.

It is apparent that increasing tissue strength does not alter the biomechanics of an athlete, but it may provide the tissue with more tolerance to load, thereby decreasing risk of injury. Loading specific structures and tissues is key; however, it is important to be aware that any additional (and possibly unnecessary) training designed to decrease injury risk is also adding to the total load the athlete experiences and may therefore inadvertently increase the risk of injury! It is also imperative that the global ‘health’ of an athlete is considered. If an athlete is not sleeping well, is highly stressed, and their performance markers are down, it might not be the appropriate time to add injury minimisation exercises. It is also important to consider the age of a runner: younger athletes tend to get more knee and bone injuries, whereas older runners experience a higher number of tendon and calf pathologies (McKean et al., 2006). This research in combination with data obtained from screening and assessments can help to guide specific exercise selection.

In Chapter 14 (Figure 14.1), it was explained that exercises can be placed on a movement specificity continuum with various running training sessions at one end and resistance training and conditioning exercises at the other. Based upon the principle of training specificity, it is therefore important that the wide variety of single joint isolated exercises designed to increase tissue capacity are also channelled into loaded movements and plyometric training. The aim of this chapter is to examine some of the global exercises that can be undertaken to reduce injury risk and how they can be coached. The chapter will also provide examples of isolation exercises that aim to increase tissue capacity.

Specific Tissue Considerations

Before appropriate exercises can be selected with the aim of improving a runner’s performance and lowering risk of injury, it is important to remember the primary function of various tissues and structures (see Table 15.1). Muscles are responsible for the generation of force; tendons connect muscle to bone and are capable of storing and returning large amounts of elastic energy; bones provide the skeletal integrity and structure for the muscles and tendons to generate force; and ligaments connecting bone to bone are responsible for maintaining stability and providing proprioceptive feedback. This is a perhaps a slightly simplistic view as none of these structures work in isolation; however, when selecting an exercise stimulus to generate an adaptive response, it is important to recall the function of the specific tissue. For example, if a runner has a history of ‘rolling’ their ankle, targeting the ligamentous tissues around the ankle that provide passive restriction and proprioception must be considered, but also the strength of the musculature around the ankle and hips.

There is no such thing as a bad exercise for an athlete. The key is in the rationale and thought process behind each exercise, which changes depending upon the goal of the athlete and the available time. The principles of variety and progression, like any training programme, must also be applied. Often athletes will try to focus on their specific weaknesses and challenge themselves with tasks they have previously not excelled at; however, care must be taken to ensure that goals are achievable as persistent failure can lead to de-motivation. It is therefore sensible to include some exercises that an athlete is good at, as well as those they are trying to improve, which is far more likely to keep them engaged with a plan. It can also be highly motivating to provide an athlete with the knowledge to progress (advance) and regress an exercise to empower them to adapt within a session in response to their global health.

TABLE 15.1 Summary of the primary function of specific biological tissues and the focus of exercise activities to achieve adaptation

The Injured Runner

Even when injured, the main aim of a rehabilitation plan should always be to keep runners running. Therefore, wherever possible, running load should be modified before using the option to take an athlete ‘off their feet’. If it is not possible for a runner to continue some light running, in addition to specific rehabilitation, it is important to ‘re-condition’ tissues for the demands of running by providing a suitable stimulus to the structures that will be loaded during gait. Moreover, continuing to maintain the total training load during periods of injury using alternative exercise (i.e. other aerobic exercise modalities and conditioning work) will continue to provide some load to maintain tissue homeostasis. Specifically, it has been shown that during running the plantar flexors produce forces equivalent to eight times body weight, the quadriceps five times body weight and the hamstrings and hip flexors two times body weight (Dorn et al., 2012). These data suggest that even if an athlete is not running, they need to sufficiently load these muscle groups with more than body weight exercises to adequately prepare their tissues for the stresses they will encounter during running. In the case of severe injuries (e.g. grade 3 strains and sprains, bone fractures), where limbs are immobilised, significant muscle atrophy and strength occurs within a few days of complete rest (Gao et al., 2018). Compared to skeletal muscle, tendons are notoriously slow to adapt (Kjaer et al., 2009) and respond more favourably to consistent cycles of loading. Therefore, wherever possible, it is important to continue to load tendons (with external resistance) whilst not running to adequately prepare the tissues for when the athlete returns to running.

Flexibility and Mobility

Whether runners should stretch regularly or not has been debated and discussed by coaches and athletes for decades. For every activity, joint, and individual there is likely to be an ‘optimal’ level of flexibility for performance and function. For distance running the optimal joint range of motion for most individuals is likely to be at the stiffer end of the stiffness-compliance continuum. In general, there appears to be an inverse relationship between flexibility and running economy (Gleim et al., 1990; Craib et al., 1996; Jones, 2002; Trehearn and Buresh, 2009; Hunter et al., 2011), suggesting that being less flexible (up to a point) is beneficial for running economy. Furthermore, chronic regular static stretching has little effect upon running economy (Shrier, 2004) and does not appear to reduce the risk of overuse injuries (Baxter et al., 2017).

Short term (as part of a warm-up), the scientific evidence indicates that a passive stretch, held for > 60 sec, allows an individual to achieve a greater range of motion at that joint, however the effect is short-lived and lasts only a few minutes (Behm, 2018). It also appears that long-duration (> 60 sec) static stretching decreases explosive power output for a short period of time (Behm et al., 2016). The reality is that runners are highly unlikely to hold a stretch for long enough, or with significant force to induce an effect, and passive stretching is therefore simply a part of their routine and psychological preparation. Moreover, recent findings demonstrate that when included as part of a warm-up routine, short duration (< 60 sec) static stretching does not impair strength and power performance (Blazevich et al., 2018) or running economy (Allison et al., 2008). Short duration static stretching can therefore be included as part of a warm-up routine in recreational-level runners, due to the positive impact of regular stretching on long-term flexibility; however, in high-performing runners, static stretching should be avoided due to the negative effects that have been reported on subsequent physical performance (Chaabene et al., 2019).

There is a strong argument that runners should utilise a more dynamic mobility (e.g. leg swings, walking lunge, squats, hurdle walkovers, etc.) and specific running drills to best prepare the body for running. Dynamic mobilisations exercise not only improves mobility through movement patterns akin to running, but can also improve posture, enhance intermuscular co-ordination and activate key muscle groups. Eccentric loading through wide ranges of movement can also increase mobility, so resistance training exercises can be used as a ‘two-for-one’ in terms of exercise prescription. There are several areas where specific joint restrictions or loss of mobility can be a risk factor of injury, and these will be highlighted within their respective anatomical locations later in the chapter.

Balance (Proprioception)

Balance is a highly complicated task-specific skill that can be developed but must be appropriate to the desired outcome. Better results have been shown by utilising postural tasks rather than an athlete on an unstable surface (Brachman et al., 2017); therefore, it is recommended that balance should be considered dynamic postural control, and hence must be trained accordingly. During periods of rapid growth around puberty, or injury, balance may deteriorate and need to be re-trained. It may be wise to tty' to keep the training exercises similar to running movement patterns, such as high knee holds or hurdle walkover drills with a medicine ball overhead. Ball throwing exercises can also be utilised and should progress from simple tasks (e.g. catching a ball whilst standing on one leg), to more complex (e.g. varying the height of the catch), and then to tasks with multiple stimuli (e.g. catch turn, land, receive a different ball). The balance challenges should be progressive by moving from slower to faster speeds, and with increasing reliance on decision-making.

How to Load

The principles of strength training were outlined in Chapter 14 and enable criticality around the specificity, overload and progression of any exercise that an athlete undertakes for the purposes of reducing injury risk. Running drills that are prescribed for specific adaptations can also form an important part of an athlete’s remedial work by providing a specific loading stimulus and improving the skill of running. Drills can be used to increase the number of low-intensity plyometric foot contacts in a session or by slowing the running action down to challenge an individual’s balance and coordination. Each category of running drills can be prescribed for multiple different reasons, but the way they are coached, and the specific focus

TABLE 15.2 Muscle contraction types, their common use in injury risk reduction and exercise prescription

of each drill, drives the adaptation. The exercises described later in this chapter move from global exercises to more specific exercises, which may suit those runners with limited time and/or provide greater focus.

When prescribing exercises, the mode of muscular contraction also needs to be considered and how this influences the outcome of a specific exercise in the context of prehabilitation/ rehabilitation (see Table 15.2). It is also wise to discuss pain during and after exercise, especially in runners with a history of injury or a present pathology. Low levels of pain (0-3 out of 10) during exercises are acceptable; however, this should settle to baseline levels within 24 hours and changes can be examined over time.

The Lower Limb

Specific global loading of the entire lower limb may be best achieved by utilising running drills to create specific adaptations and provide technical feedback. Common running drills include A and В drills; A drills largely focus on the early-swing phase leg recovery action and stability during mid-stance; and В drills emphasise the late swing phase recovery' action with correct ‘paw back’ and positioning of the foot strike relative to the hips. А-skips mimic the high knee drive and dorsiflexed ankle position associated with recovery of the swing leg, landing on the same foot before ‘skipping’ onto the other foot. В-skips again emphasise the high knee drive but add more knee extension before pulling the ankle rapidly back towards the ground under the hips, before skipping onto the opposite foot. Dribbling drills involve taking normal running steps through a reduced range of movement and more pronounced ankle dorsiflexion (flat foot ground contacts). Dribbles are often described as being ankle, calf or knee focused depending on the specific goals. Ankle dribbling drills involve taking very' small steps, with the ankles dorsiflexed, minimal knee lift (stepping over ankles), and emphasis on ground contact. Ankle dribbles are a great drill for conditioning the foot for ground impact. Calf dribbling drills incorporate more knee lift (stepping over mid-calf) and should encourage the exchange (switch) of legs whilst maintaining ankle dorsiflexion. Again, this is great for conditioning the foot and ankle to be elastically stiff and strong. Knee dribbling drills have a higher knee lift (stepping over knees) and encourage hip and glute strength to maintain postural control and push through the floor. Straight legged running (or scissors drill) are also a useful way' to reduce the braking forces using a long lever as an athlete’s foot touches down at ground contact.

Figure 15.1 display's the main technical points for the А-skip, which can each be modified or emphasised using different variations of the drill to achieve a desired adaptation. By slowing the drill down and turning it into an А-walk, balance is challenged, which will likely improve the ligamentous stability at the ankle. If the drill is sped up with shorter ground contacts,

FIGURE 15.1 Main technical points for coaching the А-skip drill

elastic energy storage capacity in the Achilles tendon is challenged, which can be progressed further by turning the exercise into plyometric bounding.

Hurdle walkovers provide another opportunity to develop coordination and balance whilst challenging the lumbopelvic complex. Simply stepping forwards and sideways over a hurdle (adapted to an athlete’s height and mobility) encourages postural control and hip mobility, and it develops specific muscular strength around the hips. As with many of the drills, by slowing hurdle walkovers down to emphasis control, stability will be challenged. Moving from a running arm action to positioning arms overhead will provide a greater challenge to the trunk musculature, and speeding up the drill will develop rhythm and add a plyometric component. Modifying the drill so a runner spends more time on one leg before switching (e.g. forward two hurdles, back one hurdle) increases time under tension, so it overloads strength endurance to a greater extent. Finally, raising the height of the hurdles if it becomes too easy will challenge an athlete’s hip mobility.

As previously discussed, global running skills can be used to develop adaptations; however, specific exercises provide the overload required for tissue adaptation based upon the required needs of the athlete. A key point that is often overlooked is the timing of prehabilitation/ rehabilitation sessions within a training week. Bone, ligament and tendon tissue responds best to brief bouts of high-intensity activity performed at high frequency (Bailey and Brooke- Wavell, 2010; Bohm et al., 2015; Baar, 2017). This does not mean athletes cannot train between bouts of loading, but it is important to consider how exercise sits alongside the programme of specific exercises. Ideally, any tendon loading exercise should be undertaken 4 hours before running, and hard runs/sessions should be on the same day as tendon loading. The exception to this is when tendon loading is introduced to a programme and a lower weight and higher repetition range is used initially (see the case study in Box 15.1). It usually takes at least a month for a tendon to display noticeable adaptation (Bohm et al., 2015) and they may require 3-4 months to settle after an injury.

For each key area we will provide coaches with a key exercise, a regression (easier) and a progression of the exercise. This is not an exclusive list; there are many exercise variants, and a great deal of this will depend on the individual athlete and their needs. The key question should always be, what tissue(s) do we need to load, and how are we going to achieve this?

The Growing Athlete

As discussed in Chapter 19, the young growing athlete needs special consideration. During puberty, adolescent athletes are likely to develop traction apophysitis (also known as ‘growing pains’) during growth spurts. These may limit performance and, in terms of developing a longterm athletic development strategy, need to be handled appropriately (with the guidance of a suitably qualified professional) to allow a child to continue participating in sport. Clinically, these can be described as the muscle and tendon pulling at the bone (usually illustrated by a tug on a jumper - no damage to the jumper, but the wearer of the jumper will be aware the jumper is being pulled). As a normal process, there is uncertainty around why some young athletes suffer more than others, but this is not a self-resolving condition and needs appropriate management/ guidance. These pains often occur in the heels (Severs) or knees (Osgood Slatters or Sinding Larsen Johansson syndrome) but can also occur at the hip (proximal rectus femoris), adductor or hamstring insertion. These issues require careful management as pain will inhibit strength and gradual/progressive loading is required through the structures to enable the athlete to perform their expected training loading. It may be wise to use isometric (static) versions of appropriate exercises for pain reduction and to apply some loading, before progressing to eccentric contractions. This should then further be progressed into landing drills and plvometrics before a return to running. It should be noted that during this time athletes may become slightly less coordinated, and balance will suffer. This is an ideal time to develop good running mechanics using walking drills and hurdle walkovers. This should be overseen by a suitably qualified practitioner and should include reassurance, education and empowerment (Esculier et al., 2018).

Bone-Related Injuries

Bony injuries exist on a continuum from periosteal inflammation to stress fractures (Table 15.3). However, it is important to recognise that not all bony pain leads to a stress fracture. Bone

TABLE 15.3 Stages of bony injury and common symptoms associated with each stage

stress injuries are caused by the load applied to the bone, exceeding the bone’s ability to tolerate that load. Bones are constantly adapting, with cells that build bone and cells that remove bone working concurrently to respond to the demand placed upon the bone. In a colloquial sense it is logical to think of bone cells as a building crew who build bone, and a demolition crew who take the old bone away. In simple terms, any bony reaction is due to either the builders not working quickly enough or the demolition crew working too quickly, and this balance can be influenced by numerous factors. If a bone struggles to remodel at the required rate, then a ‘stress reaction’ may develop.

Whilst Table 15.3 does not provide an exhaustive list of signs and symptoms, diagnosis of a bony injury needs to reflect the context of each individual athlete and their training load. If an athlete has rapidly increased their running load and it is suspected that they may not be fuelling appropriately, a cautious approach is required and the bone pain should be fully investigated. The relative energy deficiency in sport (RED-S) syndrome is covered in Chapter 18, and whilst not every athlete who gets bony pain has RED-S, it is worthwhile to think holistically about the individual. Warden and colleagues (2014) provide a clinical commentary on the Management and Prevention of Bone Stress Injuries in Long-Distance Runners, which is an excellent resource for those wishing to better understand this area. It also provides some guidance that not all bone stress injuries are equal, and there are specific areas that may be deemed more high risk compared to others (Table 15.4). All bone stress injuries should be followed up by an appropriately qualified professional, especially in the young and developing athlete.

The best strategy to prevent bone stress injuries is to have a well-conditioned, well-fuelled, well-loaded athlete. An adolescent athlete who does not sleep at least 8 hours per night has a 1.7 times greater risk of injury (Milewski et al., 2014) and improving sleep quantity may help to decrease the risk of bone stress injury (Finestone and Milgrom, 2008). Dye (2005) coined the phrase ‘envelope of function’ to describe the homeostatic balance that exists between loading and tissue capacity. If the load (either in sudden and high magnitude or low and repetitive) exceeds the capacity of a tissue, then injury is likely to occur, leading to a decreased capacity in that tissue (Dye, 2005). Athletes tend to try to return to their previous load too rapidly, which again, causes them to break down with the same injury. In order to build an athlete’s capacity and lower injury risk, there is a need to gradually increase the envelope of flmction using supramaximal overload that is sufficient for each individual athlete. Strength training can help to increase tissue capacity and has been shown to decrease injury rates compared to other types of low-level conditioning, e.g. stretching and proprioceptive balance training (Lauersen et al., 2014). As runners tend to possess higher bone mineral density than endurance athletes from non-weight-bearing sports and non-active individuals, it is important that the magnitude of loading is high and exposures brief (20-40 reps per day) to drive further bone adaptation (Umemura et al., 1997; Turner, 1998).

TABLE 15.4 Areas considered high and low risk for bone stress injuries in long-distance runners

Source: Adapted from Warden, Davis and Fredericson (2014).

Where to Focus Conditioning Efforts

Perhaps the most frequent reason given for injury is not stretching enough, and yet there is little evidence to support this theory (Yeung et al., 2011; Lauersen et al., 2014). Clinically, asymmetries in flexibility' around the calves (knee to wall test - see Chapter 7), anterior hips (Thomas test), and glutes (medial rotation) are certainly worth monitoring. Individual variation in muscle recruitment patterns has been observed during running gait. However, it is clear that the gluteals, quadriceps and calves are active during stance (Chumanov et al., 2012; Dorn et al., 2012). The quadriceps appear to be the muscle that provides the largest contribution to the stance phase of gait, and the calf complex provides the greatest contribution to propulsion (Hamner et al., 2010; Dorn et al., 2012). Gait assessment (Chapter 13) may also help guide coaches and athletes towards where their key conditioning focus should be.

Individual Anatomical Sites and How to Optimally Condition Calf Complex

Collectively known as the plantar flexors, the calf complex is responsible for large force generation during the propulsive phase of running. As running speed increases, stride length and frequency also increase, and ground contact time decreases. Therefore, the faster we run, the stifter and stronger the plantar flexors need to be. Up to 7 m.s^-1 (25.2 km.h^-1), the plantar flexors play an important role in generating vertical force to increase stride length (Dorn et al., 2012). At running speeds faster than 7 m.s^-1, the plantar flexors still have high levels of force generation but are not able to shorten quickly enough, so the hips and glutes act to increase stride frequency. Furthermore, when running at 4.45 min.km¹, the plantar flexors produce forces in excess of eight times body weight, quadriceps approximately five times body weight and hips and hamstrings two times body weight (Lenhart et al., 2014). For most runners, the calf complex is therefore an obvious area to target for both performance and reduce of injury risk.

Plantar Flexor Assessment

The following tests are commonly used to assess function and capacity in the calf complex:

• • Mobility - Knee to wall (lunge) test: see Chapter 7. Measure the distance from the big toe to the wall when the foot is flat on the floor and the knee is touching the wall. Check for asymmetry of no greater than 1 cm and distance should be greater than one third of foot length.
• • Capacity' failure - calf capacity test (straight leg and bent knee): see Chapter 7. At a rate of 1 second up, 1 second down, perform as many calf raises, first with a straight knee and then with a bent knee. Aim for within 10% of the opposite leg.
• • Plyometric capacity' test - side hop test: hopping side to side over two markers (tape) 30 cm apart, aiming for as many as possible in 30 sec. Males should target >55 reps; females >43 reps (Gustavsson et al., 2006). Compare side-to-side symmetry.
• • Single leg explosive strength - hop height: standing on one leg with hands placed on hips; hop as high as possible. Use My Jump smartphone application to assess height.

Complete Calf Exercise: Skipping or Hopping

Can be utilised by using double or single leg variants aiming to increase duration for endurance and/or hop height for power.

Gastrocnemius: Single leg calf raise (Figure 15.2)

Regression: Double leg calf raise/static single leg hold.

Progression: Weighted single leg calf raise.

Add variety with: Double leg mini bounces progressing to single leg, skipping.

FIGURE 15.2 Straight leg calf raises

FIGURE 15.3 Bent knee calf raises

Soleus: Single leg bent knee calf raise (Figure 15.3)

Regression: Double leg bent knee calf raise/static single leg hold. Progression: Weighted single leg bent knee calf raise.

Add variety with: Bent knee mini bounces progressing to single, skipping.

FIGURE 15.4 Weighted calf and Achilles tendon loading. Athletes may wish to consider only going to parallel, and going full range of motion should be used as a progression

Source: Adapted from Warden, Davis and Fredericson, 2014.

Achilles tendon loading: Calf raise on step (Figure 15.4)

Action: Eccentric (slow 3-10 sec lowering) loading going from tip toes to heel hanging below the level of the step. Progress from double leg to single leg.

Regression: Remove step to perform eccentric lowers to floor to decrease Achilles load or isometric (static) holds (>30 sec).

FIGURE 15.5 Plantar fascia calf raise with the big toe extended

Progression: Add weight (e.g. backpack, hold dumbbell) and slowly lower.

Add variety with: mini hopping, bilateral progressing to single leg, walking/running drills. Plantar fascia: toe extended calf raise (Figure 15.5)

This connective tissue extends across the sole of the foot, and often causes pain towards the heel. The plantar fascia helps to propel the foot forward during ground contact and toe-off. It should be considered a tendon and developed accordingly.

Action: Eccentric lowering with big toe pulled up (usually supported by a rolled towel). Regression: Isometric holds with toe pulled back and heel off the floor (approximately one inch) and held for >30 sec.

Progression: Add weight or perform offa step to increase range of motion.

Anterior shin (Tibialis Anterior): seated toe raises (Figure 15.6a)

The tibialis anterior muscle decelerates the foot prior to ground contact and therefore is best trained eccentrically.

Action: Seated on a chair or bench with weight plate positioned on the foot; pull toes upwards. Regression: Perform seated on floor with band anchored away from body.

Progression: Increase weight, decrease repetitions.

Add variety with: Walking on heels progressing to running drills with emphasis on ankle dorsiflexion.

Medial shin (tibialis posterior): Eccentric calf raises on a decline board (Figure 15.6b)

The tibialis posterior eccentrically resists pronation (arch lowering) of the foot and is commonly associated with ‘shin splints’ (medial tibial stress syndrome).

Action: Same as calf raise with emphasis on eccentric slow lower phase on a decline board (with the inside of the shin facing down the slope).

Regression: Isometric/eccentric lowers to floor squeezing a ball between heels. Progression: Add weight to decline board lowers.

Add variety' with: Emphasise turning the foot in, and slowly (eccentrically) turning back out. Lateral calf (peroneals): Eccentric calf raises on a decline board (Figure 15.6c)

The peroneals are responsible for everting (turning out) the foot but also have an eccentric role in stabilising the foot.

Action: Eccentric lowers on a decline board (with the inside of the shin facing up the slope). Regression: Isometric/eccentric lowers to floor with slight duck feet.

FIGURE 15.6a-c Exercises for conditioning the anterior shin (a), medial shin (b) and lateral shin muscles (c)

Progression: Add weight to decline board lowers.

Add variety with: Emphasise turning the foot out, and slowly (eccentrically) turning back in.

Proprioception (Balance)

Action: Challenge postural stability by standing on one leg and performing a ball throw- catch drill or transfer weight from side-to-side.

Regression: Double leg postural challenge.

Progression: Plyometric (jumps) with change of direction and/or unexpected nudge. Add variety with: Depth jumps and twists and turns; running change of direction drills.

BOX 15.1 CASE STUDY: 40 YEAR OLD MALE RUNNER WITH RIGHT ACHILLES TENDINOPATHY HISTORY*

Present symptoms: Mild morning stiffness, slightly stiff at the start of a run but eases off. Full training and undertaking all sessions. No other changes to established training plan.

Outcome: Single leg calf raises to failure at a rate of 1 per second. Right 36 reps/ Left 50 reps.

Coals: Pain-free running.

Tendon-specific rehabilitation plan ('Must do'):

If sore, perform 5 sets x 45 sec holds with heel approximately 2" from floor (+/- weight).

3 sets x 20 reps slow eccentric lowers (10 sec) from tip toe to floor daily (>4 hours before running) for 2-4 weeks with the aim to build capacity.

Progress to 3 sets x 20 reps (10 sec lower) eccentrically off a step daily.

Progress to weighted lowers (i.e. 5 kg in a backpack). As weight goes up, decrease the reps. 3 sets x 15 reps, 3 sets x 10 reps, 4 sets x 6 reps, etc and allow extra rest, i.e.: exercises on alternate days.

Aim for 2 sets of 4 reps with heavy weight every 72 hours.

General lower limb ('Should do'):

Plantar flexor strength - Calf raises and soleus raises.

Plyometric progressions from double leg mini bounces, single leg mini bounces, double leg high bounces, single leg hops, etc.

Supporting rehab ('Could do'):

Glute strengthening plan including but not exclusively - side plank, bridges, crab walks, single leg RDL, clams.

Add on to sessions:

A-skips - emphasising ground contact and to provide side-to-side comparison.

Hurdle walkovers - postural and lumbopelvic control.

Review Outcomes: Single leg calf capacity test Right vs. Left. Hopping side to side (as many as possible in 30 sec) comparison right vs. left.

*Diagnosis from suitably qualified professionals with all other potential causes excluded and the athlete having a clear understanding of the pathology. Rehabilitation plans are uniquely specific and should be a collaboration of all those supporting an athlete.

Foot

The foot works primarily to transfer force. The Achilles functions as a spring to store and return elastic energy, and the plantar fascia on the sole of the foot acts with the big toe to work as another spring. Much debate exists over the role of foot type, and whilst little consensus exists, it may be better to acknowledge that there is little that can be done to change it. Orthot- ics and shoe type only act to shift the focus of loading; however, this approach may be required only in some runners at specific times. High arched rigid feet are very stiff springs and the force gets pushed up into the Achilles and shin bone. A flatter foot may be more flexible and place more demand on the supporting musculature (calf, medial and lateral shin muscle groups) and will need a slower increase in loading or extra support through the running shoe.

Rotation on the Spot (Barefoot)

Action: In standing on one leg, rotate in a full circle by slightly rocking from heel to toe and across the arch of the foot.

Regression: Toe curling on the spot.

Progression: Low-grade plyometrics.

Add variety with: Performing in sand.

Knee

The following tests are commonly used to assess function and capacity around the knee:

• • Single leg squat test: perform as many single leg squats to and from a chair continuously.
• • Vertical jump testing (see Chapter 7).

Quadriceps strength is known to be a risk factor for knee-related pathology; therefore any gain in force producing capability will likely reduce injury risk and improve running economy. Squat exercise (see Chapter 14).

Regression: Wall squat (pain-free position) trying to use a duration of > 30 sec holds. Progression: Single leg squat

Add variety with: Step-ups (concentric), step downs (eccentric), hops and skips, box jumps.

Hips (Anterior)

The front (anterior) of hips and the ability to flex the hip are often overlooked and are a common site of injury in adolescent runners.

Reverse Nordic exercise (Figure 15.7)

Action: From a kneeling position and pivoting from the knees, move slowly (10 sec) backwards towards the heels, keeping shoulders, hips and knees aligned (no lower back hyperextension).

Regression: Slow squat to a chair with minimal ankle bend, taking 10 seconds to lower to chair.

FIGURE 15.7 Reverse Nordic exercise

Progression: Weighted reverse Nordic (holding weight to chest).

Add variety with: Single leg step-up, step downs, single leg squats.

Abdominals

The ‘core’ has received a great deal of attention over the past decade, and it might be wise to just think about it as two sets of muscles: deep muscles that have a stability role and more superficial muscles that act as the prime movers. Most multi-joint general exercises (e.g. squats, step-ups, lunging, jumping, etc) will always involve the abdominals. Based upon this, it is questionable whether isolation exercises for developing specific muscles within the trunk are necessary for non-injured runners. Three categories of exercises tend to be used for this purpose, and may have utility in runners who suffer from low back pain: deep stability' exercises (i.e. Pilates), contraction moving exercises (e.g. sit-ups) and anti-rotational exercises (i.e. stiff trunk with weight moving side to side or resisted perturbations). No one type of exercise is superior to another, and it is always good to evaluate function and build an athlete’s individual program based upon their needs.

Side plank with dynamic hip flexion (Figure 15.8)

Action: Lie on your side supporting your body weight with forearm (elbow directly under shoulder) and feet. There should be alignment between shoulders, hips, knees and ankles. Flex top leg towards chest, maintaining a stiff trunk and bottom leg position. Regression: Side plank on knees (Figure 15.8).

Progression: Single leg stand moving a resistance band across the body.

Add variety with: Pilates, variety of standard sit-ups and leg lowers, dynamic wood chops with weight.

Cluteals

A great deal of focus has been placed on the role of ‘glutes’, whether the deep intrinsic gluteal muscles that stabilise the hip, or the gluteus maximus which acts to propel an athlete

FIGURE 15.8 Long lever side plank with dynamic knee flexion (left) and short lever side plank (from knees) with upper body stimulus (right) forward during late stance phase. Research suggests that improving glute strength may not influence running mechanics (this potentially needs gait retraining) but may offer some injury resistance due to increased muscle capacity (Willy and Davis, 2011, 2013; Baggaley et al., 2015) and improve running economy (Blagrove et al., 2018a). Multi-joint single leg exercises such as step-up, single leg glute bridges and lunging patterns produce the highest levels of muscle activation in both the gluteus maximus and intrinsic gluteal muscles (Reiman et ah, 2012; Neto et ah, 2020) and so should be prioritised in exercise selection. Even bilateral multi-joint exercises such as glute bridge, squats, deadlifts and hip thrusts develop very high levels of activation in the gluteal muscles compared to isolation-type exercises such as clams, side lying leg raises and prone (face down) position leg raises (Reiman et ah, 2012; Neto et ah, 2020).

Iliotibial band (ITB) pain/syndrome is often thought to be a knee pathology. It is painful around the knee, but the force is transferred by the ITB from the gluteals. The ITB itself has a high tensile strength and can’t be stretched, but it has pain receptors, which is why pressing or rolling it hurts but does little to change the length. To alter the load around the knee (via ITB) careful evaluation of the hip mobility (especially medial rotation) and pelvic drop (Trendelenburg’s sign) should be undertaken to prescribe mobility or strengthening exercises. Bulgarian split lunges (foot on bench behind) should be in a program as they condition both the front leg (strength) and the rear leg to the shearing forces of the ITB. The exercise can be advanced by bringing the rear foot closer to the glutes (increased knee flexion), adding weights or progressing to staggered stance plyo- metric jumps.

Gluteus maximus: Hip thrust (Figure 15.9)

Action: Position shoulders across a chair or bench and knees at a right angle. Place a plate or bar across the hips. Starting with knees, hips and shoulders aligned, lower the hips down until they reach just above the ground and return to the start position.

Regression: Glute bridge with resistance band (Figure 15.9)

Progression: Step-up

Add variety with: Adding weight, single leg deadlift, single leg squat.

Intrinsic gluteal muscles (gluteus medius/minimus/piriformis, etc.): Side plank (Figure 15.8)

FIGURE 15.9 Start position of the hip thrust exercise (left) and top position of the glute bridge with resistance band (right)

Regression: Side lying abduction (leg raise).

Progression: Side plank with weight.

Add variety with: Hip drops/hitches (off of a step), clams, deadlifts.

Adductors

The adductors are used to stabilise the hips during the stance phase of running and act as a hip extensor during late stance (push-off).

Copenhagen adductor bridge exercise

Action: Same as the side plank exercise but with top foot only positioned on a low bench, with bottom leg hanging free.

Regression: Adductor bridge from knee off bench/chair/box.

Progression: Weighted adductor bridge.

Add variety with: Squats, sumo squats, lunges, lateral lunges.

Hamstrings

Higher levels of hamstring muscle strength have been associated with decreased injury rates and increased force production during locomotion. Runners need to build capacity and subsequently develop specific strength required for their own needs/deficits. Proximal hamstring tendinopathy is a common pathology in distance runners, with a similar aetiology' as Achilles tendinopathy. The tendon attaching the hamstrings to the pelvis becomes thicker and stiff, sometimes limiting performance. Whilst little scientific research presently exists outlining how to manage this injury, the use of eccentric loading appears to be beneficial.

Nordic hamstring exercise (Figure 15.10)

Action: Kneel down with ankles anchored by a partner or fixed object. Maintaining alignment between knees, hips and shoulders, lower hips and torso forward slowly towards the ground. Avoid any flexion at the hips or through the spine.

Regression: Band-assisted Nordic hamstring exercise.

Progression: Weighted Nordic hamstring exercise.

Add variety with: Arabesques, long lever hamstring bridges, Romanian deadlifts.

Upper Body

The upper body should not be neglected as the running arm action counter-balances rotations through the trunk caused by forces generated by the legs. The upper limb can be conditioned specifically by practicing running drills and performing hurdle walk-overs. It may also be prudent to add some upper limb exercises to general conditioning routines. For example, during a step-up, a shoulder press could be added, or a side plank could include holding a weight in the top arm (Figure 15.8).

FIGURE 15.10 Nordic hamstring exercise (band-assisted version)

BOX 15.2 EXAMPLE CIRCUIT FOR DISTANCE RUNNERS WITH A MUSCULAR CAPACITY FOCUS

Conditioning Circuit (2x Per Week)

Calf raises (Straight and bent knee)

Squats Hip hitches Step-ups Plank Side plank

Banded Nordic hamstring exercise Skipping

Start with body-weight resistance and 3 sets of 20 reps on each exercise. Over time, lower the repetitions but add resistance (e.g. 3 sets of 12 reps plus 5 kg; 3 sets of 6 repetitions plus 12 kg, etc).

Warm Up Drills (at the Start of Interval Training Sessions,

2x Per Week)

Hurdle walkovers (forwards and sideways) 6-8 hurdles A-Skips 30 m B-Skips 30 m Scissor runs 30 m

Focus on building up the volume and skill initially (2-4 sets per exercise), progressing to increasing the speed and force of contraction.

Summary

Improving muscle strength and capacity does not necessarily affect gait or running movement patterns. It is more commonly thought that these adaptations provide the tissues with an increased tolerance to the load experienced during running, and runners are therefore less likely to be injured. Runners should think carefully about the holistic total load they experience before high volumes of‘extra’work are introduced. An under-fuelled and stressed athlete with a poor sleep pattern is significantly more likely to get injured and recover poorly. This chapter has offered sensible start points for a runner to start conditioning exercises; however, it is important that athletes ‘buy in’ and understand the benefits so they can be empowered to make sensible decisions around their loading and progressions. When a runner develops an injury and is off their feet, adapting exercises to maintain loading and muscle strength (and maybe even gain strength) is important so they can return to the sport without re-injury. This chapter is not a definitive list, and there are many ways to achieve the same results, but conditioning exercise prescription needs to consider an athlete’s training age and injury history to provide the best plan for each individual. The plan should be athlete-centred, focusing on long-term athletic development, and decisions should involve all parties. Prescription of exercises should use an adaptation-led approach that targets key tissues and utilises the best stimulus to achieve positive changes to the integrity of that tissue.

PART III