Don’t clam up over lower limb exercises



I regularly find myself debating this exercise with students, new staff, and part-time staff all from different clinical backgrounds and I always find myself asking them – “Why is that patient doing clams?”

For those unsure of the terminology, the “Clam” exercise is designed to activate the external rotators of the hip, performed in side lying with limited pelvic / lumbar rotation.

Firstly I’d like to make it clear that this exercise does have a place in some rehab plans and I am not adverse to including it as part of a program where necessary – but I strongly disagree with it being a mainstay in rehabilitation plans. Purely going from anecdotal evidence, people seem to use clams as a way of increasing endurance of the glutes, particularly glute med. Often prescribing high sets and reps to target the endurance component of the muscles. Previous literature has suggested that Maximum Voluntary Contraction (MVC) of greater the 50% is required to produce any strength gains in an individual muscle (Atha 1981). Figure 1 below demonstrates the EMG activation of glute med during 2 clam exercises, at 30 and 60 degrees hip flexion. Its clear from this study that the activation of glute med is below the required level to achieve any strength gains.

Glute med (if it ever did work in isolation, which I don’t think it does) would concentrically abduct the hip, isometrically stabilise the pelvis and lower limb, and eccentrically control adduction and internal rotation. The best types of activity to stimulate these actions are going to be weight bearing exercises (Figure 1); (Krause et al 2009).

There is evidence to suggest that the posterior portion of glute med is deactivated with any degree of hip flexion, with the bias for primary movement coming from gluteus maximus (Delp et al 1999). This said, Di Stefano et al’s (2009) study produced similar glute med activation at 30 and 60 degrees hip flexion. Either way, my argument is the same – clams probably aren’t working the structures you intend to target.

Reference: DiStefano 2009 here

Clinical Reasoning

My question to clinicians who regularly use clams is always “why?”. What is the purpose of this exercise? At the moment, I work with an elite athletic population. How often in their training and/or competition do they have to externally rotate a flexed hip in an open chain from a side lying position? Never. Even in standing, I can only think of them opening up their hip to control a ball in mid-air but then they are mainly using hip flexors to activate that movement – something we strictly instruct them not to do with a clam. So now that we can’t think of a transferable example for this exercise, I would ask “why are we doing high reps and sets of an exercise we don’t need to do?”

Problem solving

We have already said that the best exercises for glute med activation are weight bearing exercises and the reason for that is exactly the reason why we shouldn’t try and isolate glute med… in weight bearing, it will work as one part of a complex and brilliant kinetic chain. This was highlighted in a very interesting study recently by Kendall et al (2013) who used a nerve block on the superior gluteal nerve and then performed the Trendelmberg test. Even with a neural block to the gluteal muscles, patients maintained pelvic alignment through the step test, highlighting that in isolation, the glutes alone do not support the pelvis.

One of my preferred, early stage exercises to improve hip control / stability is a single leg isometric movement (figure 2).

Figure 2: Single leg isometric glutes
Figure 2: Single leg isometric flutes (brilliantly demonstrated by @riarottner)

The patient is instructed to rest the contralateral leg against the wall for balance only. All of the body weight should be through the standing leg. Explain to the patient that their foot is superglued to the floor, but you want them to rotate their thigh out (encourage external rotation). There should be no movement from the upper body, bum should be “tucked in” with text book posture and they should hold this contraction for 10s, repeat 10 times. I promise, it will burn your glutes towards the end. Try this yourself and pay particular attention to what else happens further down the chain. You’ll see activation of the VMO and the medial arch will raise as tibialis posterior activates too. A brilliant example of the kinetic chain in action.

“Providing the patient is able to single leg balance, any exercise targeting hip control should be done unilaterally”

Now, there are examples in the patient populations where this is not an appropriate exercise. For example, early stage ACL injuries due to the torsion this creates through the femur and tibia. Instead I would adapt the exercise to something that we were all taught very early on in our physiotherapy degree – a simple small box step, placing one foot from the floor onto a step and back onto the floor – where the standing leg is the working leg. If you are strict enough with posture and lumbo-pelvic control, this is great early stage exercise for the glutes and easily progressed into a full step up, step downs, lateral steps, greater step heights etc. (For exercise progression, please see my shameless plug for my recent Model of Exercise Progression). Kendalls (2013) paper that we mentioned earlier, supports this simple trendelmberg exercise for patients with marked hip abductor weakness. Krause et al (2009) found an increased activation of glute med with single leg exercises compared to double leg stance, so providing the patient is able to single leg balance, any exercise targeting hip control should be done unilaterally.

For the non-weight bearing patients there is reasoning to perform these open chain exercises. While we have said we may not be increasing strength, we know that there is some activation occurring within the glutes so we limit an atrophy and maintain neuromuscular activation while the patient is NWB. Refer back to figure 1- the top exercise for glute med EMG is straight leg hip abduction so even with these NWB patients there are more appropriate alternatives to the clam.


Two of the core elements of physiotherapy is the ability to clinically reason and to provide effective exercise prescription. I would encourage people who regularly use any exercise, not just clams, as part of their mainstay exercise protocol to consider exactly why they are using them. I personally don’t think there are many examples where the clam is an appropriate exercise for sports medicine populations. The exception being NWB patients who are unable to control long lever exercises like single leg hip abduction. Therefore, there is an argument that the clam may quickly become an extinct creature.


Yours in sport


S&C – Can you ever be too young?

Strength and Conditioning in youth sport is more popular than ever.  Many independent gyms operate “academy” sessions to help the future rugby, football and olympic hopefuls to reach the top of their disciplines.  Initiatives such as the Premier League’s Elite Player Performance Pathway (EPPP) has lead to increased investment in the football academy’s throughout England while Rugby’s academy system has been established for a number of years, with increased specialist support being made available i.e. S&C/Sports Science/Physio support.

Not all exercises are appropriate for young athletes
Not all exercises are appropriate for young athletes

There are many stigma’s attached to Strength and Conditioning training in youth sports.  We have all heard remarks like… “Weights training stunts growth…damages the growth plates” or “Strength training will make you injury prone”.

Is this the truth?

The most commonly reported injuries sustained in youth Strength and Conditioning training are a result of incorrect technique, attempting to lift too much weight, incorrect use of equipment and the absence of a properly qualified supervision – ALL of which are easily avoided with properly programmed and coached sessions (Faigenhaum et al., 2009). The reality is that there are many peer reviewed papers available that prove the effectiveness of S&C programs and injury reduction across a wide variety of sports from Aussie rules football to rugby. While there have been numerous position statements from leading organisations such as the ASCM, NSCA and UKSCA regarding the benefits of a well designed S&C program in aiding the development of young athletes, yet the publics perception has yet to change.  The fact remains there are many benefits in youth athletes undertaking S&C training programs (when carried out properly!).


Benefits of  Strength and Conditioning for youth athletes

There are various benefits to Strength and Conditioning in youth athletes, so many in-fact it is beyond the scope of the current blog to cover them all.  Firstly consider that the World Health Organisation recognises physical inactivity as the fourth leading risk factor for global mortality for non-communicable diseases any additional physical activity that is undertaken will help combat the ill effects of modern living.  Appropriate strength training combined with aerobic and anaerobic training, along with a balanced diet, will lead to an increased amount of lean muscle mass which would be especially useful for young athletes in contact sports such as rugby and football.

“Significant gains can be seen as youth elites reach peak height velocity”

From a purely sporting and performance perspective pre-adolescent children show considerable potential for motor learning, therefore there is an opportunity to effectively develop skills such as squat and lunge patterns, running mechanics, deceleration and change of direction prior to the onset of puberty (Barber-Westin et al., 2006).  This should be achieved using exercises that are whole body in nature (no bicep curls…sorry) and aim to develop coordination and overall athleticism, which could also act as a protective mechanism against injury risks later in their sporting career.

kids bicepcurl

Puberty triggers the release of masses of hormones which are of massive benefit when trying to gain muscle mass and strength (if only I knew that 15 years ago).  This also results in changes to the muscular system and cardiovascular systems, mostly in the responses and changes noted to aerobic and anaerobic training stimuli.  While these qualities can be improved pre-puberty, significant gains can be seen as youth elites reach peak height velocity (period of quickest rate of growth, roughly 14 years old in boys/12 years old in girls, Naughton et al., 2000), while the mechanical loading undertaken during youth Strength and Conditioning will also positively influence the development of bones and connective tissues in the body.  Exercises such as sprinting, jumping, plyometrics as well as gym based work all have positive effects on the osteogenic processes.

What should young athletes do in S&C sessions?

Pre-puberty – At this stage of physical development the emphasis should be placed on neuromuscular training and consist of coaching the young athlete through various patterns and movements i.e. coaching a player not to perform a lunge pattern with a knee valgus.  Other movements to master at this stage of development are jumping, landing and change of direction skills.  Skill or game based activities are best for conditioning the aerobic system by manipulating the tasks, number of players or even the size of the area being used for the sessions.  Strength training should consist of exercises, both unilateral and bilateral, and loads appropriate for the age of the athlete.  Body weight exercises would be more than appropriate for this stage of development with a rep range of between 6-15 and 2-3 sets.

Puberty – Neuromuscular training at this stage should show a level of progression in comparison to the previously undertaken tasks e.g. progression from a bilateral to a unilateral exercise  or from basic balance exercise progressing to dynamic stabilisation exercises.  Conditioning exercises should be mostly interval based and consist of more games/skills orientated.  Strength training should show an increased complexity with more unilateral exercises and the introduction of Olympic lifts for appropriate individuals.

Adolescents – Neuromuscular training should consist of increased speed work, unilateral and dynamic stabilisation work.  Conditioning work should feature anaerobic based intervals and progressively more strenuous game/skill based work.  Strength training should progressively load the athlete unilaterally, bilaterally and in the olympic lifts (Gamble, P., 2009).


What’s not to like?  Starting a S&C program from a young age, provided it is supervised, structured correctly with appropriate progressions will enhance performance on the field and track while concurrently producing many lifestyle and health benefits.  A appropriate program will develop neuromuscular control and athleticism and gradually develop more specialised components of performance.  Ensuring this will help the young athlete reach their maximum potential and encourage physical activity throughout their lifetime.

Yours in Sport,


Cryotherapy: Therapeutic but is it clinically relevant?

ACPSEM members can access PRICE guidelines here

Try thinking of a title about Ice and avoid the temptation to put “Baby” in it!


The thing that I love about physiotherapy is that nothing is ever black & white. Things will come in and out of fashion and our understanding about interventions and treatment modalities will continuously evolve. One of the great debates is about the use of ice following injury. How long should we apply it? In what form should we apply it? Should we use it all?

I recently skimmed through the Physical Therapy in Sport journal under “Articles In Press” and saw two papers within that category alone that discussed the use of cryotherapy. (For anyone that is a geek like me and hasn’t got the Health Advance App by Elsevier, get it! ACPSEM members can access all the content for free here

The first paper was a systematic review (Martimbianco et al 2014), which instantly lost my attention, from my point of view they combine the conclusions of a multitude of papers and varying methodologies (all with their own unique methodological flaws) to create a super-conclusion that most of the time isn’t clinically relevant or is very noncommittal. Essentially, systematic reviews are literature stereotyping. In this case, said paper based a lot of its findings on papers from in the early 1990’s. It concluded that there was not enough evidence to draw a definitive conclusion on the use of cryotherapy following ACL reconstruction.

The second paper however, provoked a bit more thought. This study was by Phil Glasgow, Roisin Ferris and Chris Bleakley – with Glasgow and Bleakley from the recent POLICE guidelines fame – who better to critique the use of ice?
Glasgows paper was a randomised trial looking at the effects of cold water immersion (CWI) comparing different temperatures and durations of immersion on Delayed Onset Muscle Soreness (DOMS). It was this paper that inspired the forthcoming discussion…


What do we think we know about cryotherapy?


The first thing to distinguish is the method of cryotherapy; in what form should ice / cold be applied? Cryotherapy comes in forms of crushed ice to blocks of ice, buckets of cold water to cold water baths, compression devices to good old-fashioned ice spray on the side of the pitch. In any form, the proposed clinical benefits encourage a pumping effect on vascular system to encourage blood flow, nutrient and waste transportation (Wilcock, Cronin & Hing 2006). Then there are psychological benefits of feeling more “awake” and less fatigued (Wilcock et al 2006). A recent Cochran review (Bleakely et al 2012) found that CWI is superior to passive intervention at reducing muscle soreness. (I know, I slate systematic reviews then use them to my advantage). The point I’m getting at is that of all the proposed benefits of cryotherapy, the most weight is behind the subjective benefits. Take Glasgows recent paper; The control groups scores of VAS pain following eccentric hamstring exercises were 20% higher than one of the intervention groups that underwent 10 minutes immersion at 6ºC (see image below source). The results were not statistically significant but they do look clinically relevant. These percentage differences do not have to be statistically significant for them to have a major benefit in elite sport, where marginal gains has now become a specialised role in itself thanks to Dave Brailsford and the British Cycling team. Everyone is looking for that extra percent to enhance performance & results.



Where does ice fit in the treatment room?


If we return to the basic scientific theory underpinning cryotherapy, we think that it decreases metabolic activity and therefore limiting secondary hypoxic damage – essentially reducing risk of secondary injury. The injury has happened, there is nothing we can do about that, but we can prevent it worsening. Secondary hypoxic damage not only weakens affected tissues, but the associated swelling can effect surrounding tissues. In steps the counter argument…

It has been found that tissue temperatures below the subcutaneous layers are very difficult to influence due to the highly sophisticated homeostatic systems in place. Bleakley, Glasgow & Webb (2012) found the changes in tissue temperature are not enough to influence metabolic activity. However we do know that CWI will reduce skin temperature, even if it doesn’t affect tissues below (Algafly & George 2007). We also know how important the skin is in feeding information back to the CNS. It plays a huge role in proprioception and nociception.


In our treatment room, we still advocate the use of ice despite the emergence of this new understanding. What has changed in recent years is our thought process behind what is happening as a result of the ice. Instead of using cryotherapy in isolation to limit swelling, we now combine it with compression (which is proven to assist with swelling and decreasing CK levels etc) to reduce pain. For more proximal soft tissues injuries, we have the luxury of a Game Ready machine to compress and cool affected areas. However for more distal injuries, e.g. Following an ankle sprain, we will encourage the player to submerge their foot in a bucket of 1/3 ice and 2/3 water. As soon as the foot goes numb, we begin some appropriate movements (cryokinetics) depending on injury location, structures involved etc. By doing this, we believe the hydrostatic pressure of the water will act as local compression while the ice provides appropriate analgesia. The analgesia then allows us to begin some loading of damaged structures – thinking back to the POLICE guidelines that advocate Optimal Load. Every stage of this treatment is clinically reasoned. The movements undertaken should not exceed normal ranges of movement and must be pain-free.


Lets wrap it up…

At the moment, cold water immersion is commonly used as a recovery modality from exercise, especially exercises that elicit DOMS, but with very little empirical evidence to support this. Despite this, we have subjective improvements in pain following any ice interventions. If we can accept that and build that into our clinical reasoning, then we have a way of removing pain from our limiting factors and enabling us to introduce movement to an injured structure. So, although we can’t clinically justify the use of cryotherapy as a recovery modality, I would advocate it as part of a treatment & rehabilitation program.


Yours in Sport,




Game ready professionally photographed in my kitchen

Screening: A window or just smoke?

So this our first attempt at a blog and we have decided to make the task that little bit harder by co-writing it! We hope to develop the blog as we progress covering topics (old and new) in the world of Sports Science and Medicine as well as delivering insights into our roles and how we work as part of a Multi-disciplinary team. We considered a few topics to christen our new blog, trying to emphasise the importance of communication and teamwork in a multidisciplinary team. Working in professional football, we have just conducted our end of season screening with all of our squads, from 1st team down to under-9s.

sceptical baby

“So because I’m no good at planks, I’m bound to get injured..? Hmm”


The first thing we want to emphasise is that screening and testing is not the be all and end all of injury prevention and performance development. We ourselves are sceptics and regularly question what we are actually looking at and what the results mean. Are we testing what we think we are testing? However, if you can maintain this mind-set, the use of screening is very useful indeed.


As an athlete experiences new exercise’s they will, through experience and adequate coaching, improve their understanding of what is required and therefore become better at that exercise. The tests that are used in the physical screening are, by nature, subject to the same learning effect. If the players struggle with an exercise at the start of pre-season, their naturally competitive nature means they will try harder at that test in the next screening. This can make it difficult to distinguish between actual improvements and the athletes increased awareness of what is required for a “good score”. Do they just get better at just that test or are they showing actual improvement??


It is basically impossible to cancel out the learning effect but by carefully selecting the other tests used in a testing/screening process we can try to identify common issues e.g. hip hike or knee valgus hidden in an Overhead squat may present itself in a single leg variation of a squat or lunge. It is also important not to coach the athlete through the movements so we can get a true picture of what movements come naturally to them..


“Screening is a snapshot of that athlete at a given time on a given day”


From a Physiotherapists’ perspective, we can use the screening to gather some very important objective outcome measures. This can provide us with some valuable pre-injury data that can be referred back to later in the season following an injury to a player, while from a Strength and Conditioning view baseline testing acts as the foundation for which subsequent training programs should be built. We only screen and test our healthy players, so any current injuries are not recorded. This way, we know that when the player was fit and competing on the field, they were able to score “X” in “Y“ test, so we should aim for at least those scores again before we consider them able to return to training. There is a debate that the results obtained from screening are a snapshot of that athlete at a given time on a given day, conducted a week earlier or later and we may have completely different scores. We agree. For this reason, it is essential that screening is not relied upon all season. We conduct Pre-Season, end of pre-season, Mid-Season and End-Season assessments to give us a “snap-shot” of the players through a competitive season. It is important to consider two key aspects of screening and testing, those being the;


Validity does the test you are using actually measure the thing you are trying to test for?

And Reliability;are the scores/results consistent? Is it repeatable? Any test cannot be considered valid if there is no reliability in the test- if the test is not consistent and has no repeatability then the testing method is invalid.


The answer? Screen EVERYDAY…


But away from all the formal data and testing environments, we continuously monitor other outcome measures such as heart rate variability, mood questionnaires, GPS data etc. as well as actually just looking and watching the athlete’s train and play. Essentially, this is screening all season, just not in our lab coats with a goniometer, optojump and a piece of paper.

Screening should confirm or deny your clinical assessments. It should not guide your treatment, programming or management. We use a variety of single planar and multi-planar tests, looking at rotational control and anti-rotational control, speed, strength and jump tests but essentially these movements are building blocks to allow our athletes to play sport. Screening allows us to conduct controlled, repeatable tests to give us an indication (not a definition) of movement patterns, strength, speed and control, all invaluable measures that we cannot gain on the field of play.


Essentially, if you know your players well enough, you should be able to predict who will have limited hip mobility, or who will produce the strongest isometric hamstring recordings, who requires additional speed or gym work, but you now have objective numbers and scores to work from so for your next screening date, you would hope to have influenced those scores.


Yours in Sport,


Conor and Sam

me and conor