Part of being a physiotherapist, who is involved with athletes, is finding solutions to, at times, difficult problems. So, when I read a study, which provides not only interesting findings, but helps me assist my patients to achieve their absolute best during rehab, quite frankly, I’m stoked.
That’s the exact feeling I had when reading the Lenhart et al (2014) paper on hip muscle activation during running at different speeds. These researchers wanted to examine the difference in activation of muscles, surrounding the hip, at different stepping rate paces including, 90%, 100% and 110% of their regular pace. Increasing running step rate (cadence) has previous been advocated as a method of decreasing the load transmitted through the hip, therefore allowing better recovery and rehab, whilst still maintaining running.
If you’ve had a running injury or have been experiencing discomfort whilst running, pay close attention as some of these findings may help you get back on the track sooner and for longer!
At the normal pace (100%) the muscle which worked the hardest on ground contact was the gluteus medius – A very important muscle for hip stability, as it resists the hip dropping on ground contact and keeps the trunk upright. In fact, the sum of the forces of the gluteus medius and minimus was 3.5 times that of the gluteus maximus. Something to consider for all runners! During the early and late swing phase, the iliacus and semimembranosis were most active, respectively.
The most interesting and rehab relevant findings were when the researchers examined running at higher stepping rates.
At ground contact, the load through the gluteals, rectus femoris (quadricep/hip flexor), adductor magnus (groin/small ‘hamstring’ role) and piriformis (deep hip external rotator) all decreased. However, this increase in step rate also resulted in higher hamstring muscle load.
As the limb was off the ground (swing phase) the load through tensor fascia latae (hip flexor, important muscle for ITB issues), gluteus minimus, rectus femoris, adductor brevis (groin) and the hamstrings and glutes (especially later in swing), all increased.
The changes in gluteal muscle activation (-10%) appear to be proportional to the increase in step rate (+10%). This is likely due to the glutes role in maintaining vertical alignment, of the body, as well as braking, which is reduced as step rate increases. The increased activation of iliacus, rectus femoris, sartorius, tensor fascia latae, gluteaus minimus and adductor brevis is due to each having either a primary or secondary role as a hip flexor.
The recommendations from Lenhart et al (2014) are as follows;
The authors did also declare some limitations in this study. A few muscles were left out of the study and some others were simplified; the percentages of step rate were self-selected initially by participants (ranging from 2.4-3.8m/s) therefore may not be completely applicable to faster or slower speeds; all participants were healthy and thus application to injured people may yield different results. All of these are fair points, however I think the information presented creates a base for an experienced health or fitness professional to apply to their patients.
Here are your take home points;
So don’t quit running just because you’ve been having pain. Catch up with your physio and discuss ways, such as the ones mentioned above, to get you back on the track sooner and in less pain!
Lenhart, R., Thelen, D., & Heiderscheit, B. (2014). Hip Muscle Loads During Running at Various Step Rates. Journal of Orthopaedic & Sports Physical Therapy, 44(10), 766-A4.
The winter season is well and truly underway thus the busiest time of the year for field sports is upon us. Hand in hand with this comes soft-tissue injuries for the unlucky and unprepared. A significant proportion of these people will experience a hamstring injury (HSI). Check out our video for more info on Hamstring Injuries, here.
HSI’s can be as frustrating as they are common, with one study suggesting they represent 12-16% of injuries in all soccer players. The difficulty, however, arises in the recurrence of HSI with the same study suggesting 22% of those with HSI will have another within 2 months after the initial injury and 25% will re-injure the season after.
These numbers are huge and represent massive failings across a few areas:
Poor compliance/utilisation of the strength and conditioning during pre-season
Failed or poor rehabilitation post-injury
Possibly never doing either of the above!
So, how do these HSI occur in the first place and what is their mechanism?
Peak hamstring force occurs in the late swing phase (Figure 1 – panel 4 and 5, right leg) of the running gait cycle. This force increases as we increase our speed. This is where the majority of HSI occur due to the hamstring having to generate tension whilst lengthening to decelerate the knee.
Plenty of people who have experienced a HSI will tell you they did their warm-up or pre-season work. However, unless you are exposed to loads at high speed and intensity the hamstring will not be prepared. This is due to the hamstring muscles being relatively dormant during the walking or jogging gait cycle. Put simply, going for a jog does not condition your hamstrings enough for field sports. Period.
Knowing this, some canny researchers in Denmark decided to try implementing a hamstring strengthening protocol, known as the Nordic Hamstring Curl (Figure 2) and measure its impact on HSI in soccer players. This revealed some interesting results.
A reduction of 60% in new HSI and a reduction of 85% in recurrent HSI’s! Furthermore, another study reported the Nordic improved hamstring length as much as static stretching, plus all the extra strength gains.
I will add a third to this;
The reason for this is that the exercise mimics the role of the hamstring muscles during sprinting (lengthening whilst contracting) and thus can present a potential mechanism for re-injury if not introduced carefully by a professional.
A more recent paper has found that when combined with a lack of eccentric (lengthening) strength, a short Bicep Femoris long head (BFlh) increased the risk of a HSI. More specifically;
We know from previous research that a really effective way of improving muscle fascicle length is through incorporating eccentric exercises. So through incorporating eccentric exercises, such as the aforementioned Nordic, we are able to significantly reduce our injury risk due to targeting weakness and tightness! This is accurately summarised in Figure 3 (below).
Take home points:
I hope this brief overview provides some insight into why and how HSI occur and what to do in order to rehabilitate following injury. You can also use this general advice as a way to remain injury free!
If you’ve suffered HSI in the past and are looking to bulletproof yourself for the winter season, contact Roar Physiotherapy in 0421 833 801 to get started on your specific hamstring strengthening protocol today!
O’Sullivan, K., McAuliffe, S., & DeBurca, N. (2012). The effects of eccentric training on lower limb flexibility: a systematic review. British journal of sports medicine, bjsports-2011.
Petersen, J., Thorborg, K., Nielsen, M. B., & Hölmich, P. (2010). Acute hamstring injuries in Danish elite football: a 12‐month prospective registration study among 374 players. Scandinavian journal of medicine & science in sports, 20(4), 588-592.
Petersen, J., Thorborg, K., Nielsen, M. B., Budtz-Jørgensen, E., & Hölmich, P. (2011). Preventive effect of eccentric training on acute hamstring injuries in men’s soccer a cluster-randomized controlled trial. The American journal of sports medicine, 39(11), 2296-2303.
Timmins, R. G., Bourne, M. N., Shield, A. J., Williams, M. D., Lorenzen, C., & Opar, D. A. (2016). Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study. Br J Sports Med, 50(24), 1524-1535.
Now we know what the hamstrings are made of (here) and the principles of avoiding hamstring injury (here), we can move onto something heavily practical which you can sink your teeth into – The optimal hamstring rehab program, according to science.
These clever researchers have managed to assess some of the most common hamstrings exercises and from there, measure the activation of each hamstring muscle. They have therefore been able to determine which is the most targeted exercise for each hamstring muscle.
So, without further ado, what you need to know.
Low activation All exercises S > BFlh activation
To simplify this slightly, Bourne et al found that hip extension activities (e.g. RDL) preferentially activate the BFlh whereas knee flexion activities (e.g. Nordic HS Curl) preferentially recruit the semitendinosus.
These findings are vital to effective hamstring rehab as they allow a good clinician to provide a complete rehab program which targets the whole muscle group. This has the capacity to improve rehab outcomes as well as reduce reinjury when gym-based rehab programs are maintained in the long term. Furthermore, this information could be useful for those in the bodybuilding community who pursue a symmetrical and intentionally well-developed figure.
If there are any questions regarding this piece or the previous two, contact me on firstname.lastname@example.org or get in touch via Facebook @roarphysiotherapy or Instagram @roar_physio.
Roar Principal Physiotherapist
Hamstring injury rehab is a buzz topic in physiotherapy right now and rightfully so! Subsequently, I’ve been reading and listening to everything I can to provide to you a condensed version of what we know, so you can get better, faster!
Firstly, if you haven’t checked out the previous hamstring articles by Roar Physiotherapy, check them out, here and here. If reading isn’t your thing, I summarised it in a short video which can be found, here. These resources go through why we get hamstring injuries and the factors that can predict them.
To begin the conversation, let’s get into what we know about how the hamstrings are built, or their architecture. There are three hamstrings which can be divided roughly into medial and lateral groups. The medial hamstrings are made up of the semitendinosus and semimembranosus muscles and originate from the medial aspect of the ischial tuberosity (your sit bone) and insert to the medial shin bone. The lateral hamstrings are split into two heads of the biceps femoris muscle, being the long and short head. The long head starts in the same spot as the semitendinosus (medial sit bone) and the short head originates from a bony groove in the back of the femur called the linea aspera. These heads run down and insert in a few locations, but mainly to the fibular head and into the lateral collateral ligament (LCL).
The semitendinosus, semimembranosus and bicep femoris long head are all supplied by the tibial branch of the sciatic nerve. Interestingly, the short head is actually supplied by the common peroneal portion of the sciatic nerve. It remains to be seen if this could be a potential reason for so many bicep femoris muscle injuries, but is certainly an area to watch!
That was intense…
The reason it is important to understand the hamstring anatomy is because of the distinct differences in each muscle. Hamstring rehab and injury prevention should include MANY different exercises, rather than just one or two curls. This will be thoroughly explained in part three, plus all the exercises you NEED to know!