Strength is Never a Weakness

Thursday, 23 July 2015

Energy Systems of the Human Body

Energy Systems of the Human Body

By Andrew Richardson

In this article we will be looking at all the energy systems used in the human body, looking at how energy is created and stored, what energy systems are used in certain sports, how lactic acid can be used as an energy system.

The cellular respiration process that converts food energy into adenosine triphosphate (a form of energy) is largely dependent on the availability of oxygen.

Adenosine Triphosphate (ATP) is the usable form of chemical energy for muscular activity. It is stored in most cells, particularly in muscle cells. Other forms of chemical energy, such as those available from food, must be transferred into ATP form before they can be utilized by the muscle cells.[1] During exercise, the supply and demand of oxygen available to muscle cells is affected by the duration and intensity of the exercise and by the individual's cardiorespiratory fitness level. This can be based on if the sport/activity at hand is short and maximal intensity or it is long duration with submaximal effort.

There are three exercise energy systems that can be selectively recruited, depending on the amount of oxygen available, as part of the cellular respiration process to generate the ATP energy for the muscles. They are adenosine triphosphate (ATP-Pc system), the anaerobic system and the aerobic system.

Think of ATP as petrol and the human body as a car. The energy systems are 3 different speeds we can choose. ATP is broken down using the following equation (I will use two examples one scientific the other simplified);

Since energy is released when ATP is broken down, energy is required to rebuild or resynthesize ATP. The building blocks of ATP synthesis are the by-products of its breakdown; adenosine diphosphate (ADP) and inorganic phosphate (Pi). The energy for ATP resynthesize comes from three different series of chemical reactions that take place within the body. Two of the three depend upon the food we eat, whereas the other depends upon a chemical compound called phosphocreatine. The energy released from any of these three series of hi reactions is coupled with the energy needs of the reaction that resynthesizes ATP. The separate reactions are functionally linked together in such a way that the energy released by the one is always used by the other.[2]

There are 3 ways to resynthesize ATP;

- ATP–CP system/Phosphagen System: This is the primary system behind very short, powerful movements like a golf swing, a 100 m sprint, or powerlifting.

- Anaerobic system/Anaerobic Glycolysis: An example of an activity of the intensity and duration that this system works under would be a 400 m sprint.

- Aerobic system: In a 1 km run, this system is already providing approximately half the energy; in a marathon run it provides 98% or more.[3]

The next picture shows the duration of each system when in use (Aerobic and anaerobic systems usually work concurrently. When describing activity it is not which energy system is working but which predominates.[7]) As you can tell from the graph ATP-Pc system (phosphogen system) gives the most energy but for the least amount of time and the oxidative (aerobic system) gives the lowest amount of energy at the start but keeps going till it plateaus and stays consistent maintain that submaximal intensity for a long period of time. In between the two is the glycolytic system (glycolysis system) which gives nearly as much energy in a short space of time like the ATP-Pc system but can’t sustain it due to the build-up of lactic acid over a period of time.

What is Phospho-Creatine and how it is used by the body?

Michel Eugène Chevreul discovered it along with margarine. It is a legal supplement also known as an ergogenic aid. Creatine is found in the muscles, brain and testicles in stores called phosphocreatine stores/creatine phosphate stores. Creatine phosphate is readily available to the cells and rapidly produces ATP. It also exists in limited concentrations and it is estimated that there is only about 100g of ATP and about 120g of creatine phosphate stored in the body, mostly within the muscles. Together ATP and creatine phosphate are called the high-energy phosphogens

ATP and creatine phosphate (also called phosphocreatine or PCr for short) make up the ATP-PCr system. PCr is broken down releasing a phosphate and energy, which is then used to rebuild ATP. Recall, that ATP is rebuilt by adding a phosphate to ADP in a process called phosphorylation. The enzyme that controls the breakdown of PCr is called creatine kinase.

The ATP-PCr energy system can operate with or without oxygen but because it doesn’t rely on the presence of oxygen it said to be anaerobic. During the first 5 seconds of exercise regardless of intensity, the ATP-PCr is relied on almost exclusively. ATP concentrations last only a few seconds with PCr buffering the drop in ATP for another 5-8 seconds or so. Combined, the ATP-PCr system can sustain all-out exercise for 3-15 seconds and it is during this time that the potential rate for power output is at its greatest. If activity continues beyond this immediate period, the body must rely on another energy system to produce ATP. However, the usefulness of the ATP-CP system lies in the rapid availability of energy rather than quantity. This is extremely important with respect to the kinds of physical activities that humans are capable of performing.[5]

Anaerobic Glycolysis

“Glycolysis” refers to the breakdown of sugar. In this system, the breakdown of sugar supplies the necessary energy from which ATP is manufactured. When sugar is metabolized anaerobically, it is only partially broken down and one of the by-products is lactic acid. This process creates enough energy to couple with the energy requirements to resynthesize ATP.

When H+ ions accumulate in the muscles causing the blood pH level to reach very low levels, temporary muscular fatigue results. Another limitation of the lactic acid system that relates to its anaerobic quality is that only a few moles of ATP can be resynthesized from the breakdown of sugar as compared to the yield possible when oxygen is present. This system cannot be relied on for extended periods of time.

The lactic acid system, like the ATP-CP system, is extremely important, primarily because it also provides a rapid supply of ATP energy. For example, exercises that are performed at maximum rates for between 1 and 3 minutes depend heavily upon the lactic acid system for ATP energy. In activities such as running 1500 meters or a mile, the lactic acid system is used predominately for the “kick” at the end of a race.[6]

Depending on a number of factors such as age, gender, training history and injury everyone will have a different level of energy systems. What I mean by this some people are more efficient at one energy system compared to another person.

Anaerobic exercise is an exercise intense enough to trigger lactate formation. It is used by athletes in non-endurance sports to promote strength, speed and power and by body builders to build muscle mass. Muscle energy systems trained using anaerobic exercise develop differently compared to aerobic exercise, leading to greater performance in short duration, high intensity activities, which last from mere seconds to up to about 2 minutes. [7]

Anaerobic metabolism, or anaerobic energy expenditure, is a natural part of whole-body metabolic energy expenditure.[8] Fast twitch muscle (as compared to slow twitch muscle) operates using anaerobic metabolic systems, such that any recruitment of fast twitch muscle fibers leads to increased anaerobic energy expenditure. Intense exercise lasting upwards of about four minutes (e.g., a mile race) may still have a considerable anaerobic energy expenditure component. High-intensity interval training, although based on aerobic exercises like running, cycling and rowing, effectively become anaerobic when performed in excess of 90% maximum heart rate. Anaerobic energy expenditure is difficult to accurately quantify, although several reasonable methods to estimate the anaerobic component to exercise are available.[9][10][11]

In contrast, aerobic exercise includes lower intensity activities performed for longer periods of time. Activities such as walking, long slow runs, rowing, and cycling require a great deal of oxygen to generate the energy needed for prolonged exercise (i.e., aerobic energy expenditure). In sports which require repeated short bursts of exercise however, the anaerobic system enables muscles to recover for the next burst. Therefore training for many sports demands that both energy producing systems be developed.

The two types of anaerobic energy systems are: 1) high energy phosphates, ATP adenosine triphosphate and CP creatine phosphate; and 2) anaerobic glycolysis. High energy phosphates are stored in limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen, or more specifically when ATP is needed at rates that exceed those provided by aerobic metabolism. The consequence of such rapid glucose breakdown is the formation of lactic acid (or more appropriately, its conjugate base lactate at biological pH levels). Physical activities that last up to about thirty seconds rely primarily on the former, ATP-CP phosphagen system. Beyond this time both aerobic and anaerobic glycolysis-based metabolic systems begin to predominate.

The by-product of anaerobic glycolysis, lactate, has traditionally been thought to be detrimental to muscle function. However, this appears likely only when lactate levels are very high. Elevated lactate levels are only one of many changes that occur within and around muscle cells during intense exercise that can lead to fatigue. Fatigue, that is muscle failure, is a complex subject. Elevated muscle and blood lactate concentrations are a natural consequence of any physical exertion. The effectiveness of anaerobic activity can be improved through training.[12]

Before we go into the aerobic system, there is usually another energy pathway that is forgotten about. That is the Cori Cycle.

Cori Cycle

The Cori cycle (also known as the Lactic acid cycle), named after its discoverers, Carl Ferdinand Cori and Gerty Cori,[13] refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate.[14]

The cycle's importance is based on the prevention of lactic acidosis in the muscle under anaerobic conditions. However, normally before this happens the lactic acid is moved out of the muscles and into the liver.[15]

The cycle is also important in producing ATP, an energy source, during muscle activity. The Cori cycle functions more efficiently when muscle activity has ceased. This allows the oxygen debt to be repaid such that the Krebs cycle and electron transport chain can produce energy at peak efficiency.[16]

Scientific Photo

As the picture below shows a detailed pathway of how energy is used a transported from an anaerobic route to an aerobic route.

To finish the cycle we must look at the aerobic pathway.

Aerobic Pathway

Krebs cycle (citric acid cycle) – is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats and proteins into carbon dioxide and chemical energy in the form of adenosine triphosphate (ATP)

Aerobic capacity refers to the maximum amount of oxygen consumed by the body during intense exercises, in a given time frame.[18] It is a function both of cardiorespiratory performance and the maximum ability to remove and utilize oxygen from circulating blood. To measure maximal aerobic capacity, an exercise physiologist or physician will perform a VO2 max test, in which a subject will undergo progressively more strenuous exercise on a treadmill, from an easy walk through to exhaustion. The individual is typically connected to a respirometer to measure oxygen consumption, and the speed is increased incrementally over a fixed duration of time. The higher the measured cardiorespiratory endurance level, the more oxygen has been transported to and used by exercising muscles, and the higher the level of intensity at which the individual can exercise. More simply put, the higher the aerobic capacity, the higher the level of aerobic fitness. The Cooper and multi-stage fitness tests can also be used to assess functional aerobic capacity for particular jobs or activities.

The degree to which aerobic capacity can be improved by exercise varies very widely in the human population: while the average response to training is an approximately 17% increase in VO2max, in any population there are "high responders" who may as much as double their capacity, and "low responders" who will see little or no benefit from training.[17] Studies indicate that approximately 10% of otherwise healthy individuals cannot improve their aerobic capacity with exercise at all.[19] The degree of an individual's responsiveness is highly heritable, suggesting that this trait is genetically determined.[17]

Different Sports & Their Energy Systems

Depending on the sport it will ultimately affect what sort of energy system it will use. Here are a few pictures which will help you understand better what each energy system does at specific time points. Remember all energy systems work together some are more dominant than others during specified intensities.

Here are a list of sports which show which energy system's they rely on.

Journals on all Energy Systems

Here are some of my favourite journals on each of the energy systems;

Aerobic

- Gastin, P. B. (2001). Energy system interaction and relative contribution during maximal exercise. Sports medicine, 31(10), 725-741.

- MacVICAR, M. G., Winningham, M. L., & NICKEL, J. L. (1989). Effects of aerobic interval training on cancer patients' functional capacity. Nursing research, 38(6), 348-353.

- Lee, C. P., & Ernster, L. (1968). Studies of the Energy‐Transfer System of Submitochondrial Particles. European Journal of Biochemistry, 3(4), 385-390.

Anaerobic (ATP-Pc)

- Spriet, L. L., Soderlund, K. A. R. I. N., Bergstrom, M. A. T. S., & Hultman, E. R. I. C. (1987). Anaerobic energy release in skeletal muscle during electrical stimulation in men. Journal of Applied Physiology, 62(2), 611-615.

- Bangsbo, J. (1996). Oxygen deficit: a measure of the anaerobic energy production during intense exercise?. Canadian Journal of Applied Physiology, 21(5), 350-363.

- Bangsbo, J., Gollnick, P. D., Graham, T. E., Juel, C., Kiens, B., Mizuno, M., & Saltin, B. (1990). Anaerobic energy production and O2 deficit‐debt relationship during exhaustive exercise in humans. The Journal of Physiology, 422(1), 539-559.

Glycolysis

- Hill, D. W. (1999). Energy system contributions in middle-distance running events. Journal of sports sciences, 17(6), 477-483.

- Connett, R. J., Honig, C. R., Gayeski, T. E. J., & Brooks, G. A. (1990). Defining hypoxia: a systems view of VO2, glycolysis, energetics, and intracellular PO2. Journal of Applied Physiology, 68(3), 833-842.

- Duffield, R., Dawson, B., & Goodman, C. (2005). Energy system contribution to 400-metre and 800-metre track running. Journal of Sports Sciences, 23(3), 299-307.

Cori Cycle

- Vandewalle, H., Péerès, G., & Monod, H. (1987). Standard anaerobic exercise tests. Sports Medicine, 4(4), 268-289.

- Brooks, G. A. (1991). Current concepts in lactate exchange. Med Sci Sports Exerc, 23(8), 895-906.

- Billat, V. L., Sirvent, P., Py, G., Koralsztein, J. P., & Mercier, J. (2003). The concept of maximal lactate steady state. Sports Medicine, 33(6), 407-426.

I hope you found this helpful in explaining what the energy systems are

Regards

Andrew

References

1. Fox, Edward (1979). Sports Physiology. United States of America: Saunders College Publishing. pp. 7–8.

2. Fox, Edward (1979). Sports Physiology. United States of America: Saunders College Publishing. pp. 8–9.

3. James Madison University Strength and Conditioning Program (link is dead)

4. Fox, Edward (1979). Sports Physiology. United States of America: Saunders College Publishing. p. 9.

5. Fox, Edward (1979). Sports Physiology. United States of America: Saunders College Publishing. pp. 9–11.

6. Fox, Edward (1979). Sports Physiology. United States of America: Saunders College Publishing. pp. 11–12.

7. ^ a b Medbo, JI; Mohn, AC; Tabata, I; Bahr, R; Vaage, O; Sejersted, OM (January 1988). "Anaerobic capacity determined by maximal accumulated O2 deficit". Journal of Applied Physiology 64 (1): 50–60. Retrieved 14 May 2011.

8. ^ Scott, Christopher B (June 2005). "Contribution of anaerobic energy expenditure to whole body thermogenesis". Nutrition & Metabolism. 14 2. doi:10.1186/1743-7075-2-14. Retrieved 14 May 2011.

9. ^ Di Prompero, PE; G. Ferretti (Dec 1, 1999). "The energetics of anaerobic muscle metabolism" (PDF). Respiration Physiology 118 (2-3): 103–115. doi:10.1016/s0034-5687(99)00083-3.

10. ^ Scott, Christopher B (2008). A Primer for the Exercise and Nutrition Sciences: Thermodynamics, Bioenergetics, Metabolism. Humana Press. p. 166. ISBN 978-1-60327-382-4.

11. ^ McMahon, Thomas A (1984). Muscles, Reflexes, and Locomotion. Princeton University Press. pp. 37–51. ISBN 0-691-02376-X.

12. Energy Proportion Graphs

acs.org/content/acs/en/education/whatischemistry/landmarks/carbohydratemetabolism.html
Nelson, David L., & Cox, Michael M.(2005) Lehninger Principles of Biochemistry Fourth Edition. New York: W.H. Freeman and Company, p. 543.

15. ^ a b Medbo, JI; Mohn, AC; Tabata, I; Bahr, R; Vaage, O; Sejersted, OM (January 1988). "Anaerobic capacity determined by maximal accumulated O2 deficit". Journal of Applied Physiology 64 (1): 50–60. Retrieved 14 May 2011.

16. ^ Scott, Christopher B (June 2005). "Contribution of anaerobic energy expenditure to whole body thermogenesis". Nutrition & Metabolism. 14 2. doi:10.1186/1743-7075-2-14. Retrieved 14 May 2011.

17. ^ Di Prompero, PE; G. Ferretti (Dec 1, 1999). "The energetics of anaerobic muscle metabolism" (PDF). Respiration Physiology 118 (2-3): 103–115. doi:10.1016/s0034-5687(99)00083-3.

18. ^ Scott, Christopher B (2008). A Primer for the Exercise and Nutrition Sciences: Thermodynamics, Bioenergetics, Metabolism. Humana Press. p. 166. ISBN 978-1-60327-382-4.

19. ^ McMahon, Thomas A (1984). Muscles, Reflexes, and Locomotion. Princeton University Press. pp. 37–51. ISBN 0-691-02376-X.

20. https://en.wikipedia.org/wiki/Bioenergetic_systems

Andrew Richardson, Founder of Strength is Never a Weakness Blog

I have a BSc (Hons) in Applied Sport Science and a Merit in my MSc in Sport and Exercise Science and I passed my PGCE at Teesside University.

Now I will be commencing my PhD into "Investigating Sedentary Lifestyles of the Tees Valley" this October 2019.

I am employed by Teesside University Sport and WellBeing Department as a PT/Fitness Instructor.

My long term goal is to become a Sport Science and/or Sport and Exercise Lecturer. I am also keen to contribute to academia via continued research in a quest for new knowledge.

My most recent publications:

https://www.sciencedirect.com/science/article/pii/S1752928X19300216

https://www.sciencedirect.com/science/article/abs/pii/S1752928X19301076

My passion is for Sport Science which has led to additional interests incorporating Sports Psychology, Body Dysmorphia, AAS, Doping and Strength and Conditioning.

Within these respective fields, I have a passion for Strength Training, Fitness Testing, Periodisation and Tapering.

I write for numerous websites across the UK and Ireland including my own blog Strength is Never a Weakness.

I had my own business for providing training plans for teams and athletes.

I was one of the Irish National Coaches for Powerlifting, and have attained two 3rd places at the first World University Championships,

in Belarus in July 2016.Feel free to email me or call me as I am always looking for the next challenge.

Contact details below;

Facebook: Andrew Richardson (search for)

Facebook Page: @StrengthisNeveraWeakness

Twitter: @arichie17

Instagram: @arichiepowerlifting

Snapchat: @andypowerlifter

Email: a.s.richardson@tees.ac.uk

Linkedin: https://www.linkedin.com/in/andrew-richardson-b0039278

Research Gate: https://www.researchgate.net/profile/Andrew_Richardson7

Monday, 20 July 2015

Hamstring Heaven!!

Hamstring Injuries/Surgery/Anatomy/Exercises. Its Hamstring Heaven Here!!

By Andrew Richardson

In this article I will be looking at the anatomy of the hip and knee, the Hamstring muscles and its role, how does the hamstring tear, the surgical procedure to repair it. Then to finish looking at a range of hamstring topics. I will be making reference to my day spent in SSC (Santry Sports Clinic) in Dublin, where I learned a lot more about Hamstrings and their own Return to Play Protocol.

Structure of Hamstrings and Type of Joints at Knee, Hip and Ankle

Structure of Hamstrings

The three muscles of the posterior thigh (semitendinosus, semimembranosus, biceps femoris long & short head) flex (bend) the knee, while all but the short head of biceps femoris extend (straighten) the hip. The three 'true' hamstrings cross both the hip and the knee joint and are therefore involved in knee flexion and hip extension. The short head of the biceps femoris crosses only one joint (knee) and is therefore not involved in hip extension. With its divergent origin and innervation it is sometimes excluded from the 'hamstring' characterization.

Two photos: Left deeper anatomical analysis of the hamstrings and what is surrounding them, right photo showing the 3 parts of the hamstrings.

Function of Hamstrings

The hamstrings cross and act upon two joints - the hip and the knee. Semitendinosus and semimembranosus extend the hip when the trunk is fixed; they also flex the knee and medially (inwardly) rotate the lower leg when the knee is bent. The long head of the biceps femoris extends the hip as when beginning to walk; both short and long heads flex the knee and laterally (outwardly) rotates the lower leg when the knee is bent.

The hamstrings play a crucial role in many daily activities, such as, walking, running, jumping, and controlling some movement in the trunk. In walking, they are most important as an antagonist to the quadriceps in the deceleration of knee extension.

Clinical significance

Imaging the hamstring muscles is usually performed with an ultrasound and/or MRI.[1] The biceps femoris is most commonly injured, followed by semitendinosus. Semimembranosus injury is rare. Imaging is useful in differentiating the grade of strain, especially if the muscle is completely torn.[2] In this setting, the level and degree of retraction can be determined, serving as a useful roadmap prior to any surgery. Those with a hamstring strain of greater than 60mm in length have a greater risk of recurrence.[3]

Tear of the hamstrings muscles at the ischial tuberosity seen on MRI (coronal STIR). The arrowheads indicate the tuber and the retracted tendon stump. Significant bleeding around and into the muscles.

Use in surgery

The distal semitendinosus tendon is one of the tendons that can be used in the surgical procedure ACL reconstruction. In this procedure, a piece of it is used to replace the anterior cruciate ligament (ACL). The ACL is one of the four major ligaments in the knee. Here is a video of a semitendoinous surgery in action (WARNING GRAPHIC) https://www.youtube.com/watch?v=tQUd5JwykzY and thr ACL replacement surgery (again WARNING GRAPHIC) https://www.youtube.com/watch?v=iFniNyUpVKw

Reason for looking at knee and hip joints, is because the hamstring plays such a role in both of them.

Knee Joint

The knee joint joins the thigh with the leg and consists of two articulations: one between the femur and tibia, and one between the femur and patella.[4] It is the largest joint in the human body.[5] The knee is a mobile trocho-ginglymus (a hinge joint), which permits flexion and extension as well as slight internal and external rotation. The knee joint is vulnerable to both acute injury and the development of osteoarthritis. It is often grouped into tibiofemoral and patellofemoral components.[6][7] (The fibular collateral ligament is often considered with tibiofemoral components.)[8] Below are a few images of the knee from a range of angles.

Hip Joint

The hip region is located lateral and anterior to the gluteal region (i.e., the buttock), inferior to the iliac crest, and overlying the greater trochanter of the femur, or "thigh bone". In adults, three of the bones of the pelvis have fused into the hip bone or acetabulum which forms part of the hip region.

The hip joint, scientifically referred to as the acetabulofemoral joint (art. coxae), is the joint between the femur and acetabulum of the pelvis and its primary function is to support the weight of the body in both static (e.g. standing) and dynamic (e.g. walking or running) postures. The hip joints are the most important part in retaining balance. The pelvic inclination angle, which is the single most important element of human body posture, is mostly adjusted at the hips

Here is a good video by Nabil Ebrahiem, Professor & Chairman of the Department of Orthopaedic Surgery at the University of Toledo Medical Centre: Looking at Hamstrings Injuries.

https://www.youtube.com/watch?v=CubBXSt_NRw

Now after gaining a better understanding of the anatomy of the hamstrings and their function. We can now look at detail the assessment of a hamstring injury. I was fortunate enough to spend a day at Santry Surgery Clinic (SSC) in Dublin where I was introduced to their Hamstring assessment protocol (which is shown below). I hope you find it very useful as I did.

Assessment of Injury

Subjective: Previous history (specifically hamstrings), age (over 22), VAS, site of injury. Mechanism, Training Load. Normal subjective assessment. Walking ability. Objective, straight leg raise, prone hamstring curl at 0 degress, 45 degrees and 90 degrees. Strength. Bridge – functional ability. Hip flex/knee flex, iso contraction +/-. Bridge (weakness), location of tenderness, palpation, length of tenderness, Hip Int/Ext rotation. Thomas Test, Slump Test.

For physios here is an excellent video by Joe Keegan Physiotherapist of Loughborough Sports Injury Clinic on how to assess and treat an injured athlete with a hamstring injury.

https://www.youtube.com/watch?v=n9wZEuB2LMA

Factors Affecting Progress

- Negative: Aclusion fracture, Grade III hamstring rupture, Recurrent Hamstring Injury, Involvement proximal tendon, large and deep hematoma, excessive slow speed stretching injury. High Vas pain?

- MRI Needed? Aclusion, Grade III rupture. Proximal/Distal Tendon injury. Excessive stretching injury.

- Positive: Gr1/Gr2 hamstring Injury, pain free walking within 24 hours, short muscle tear on MRI.

Diagnostic and Rehabilitation

Acute injury Management: Compression bandage, ice bi-hourly for 20 minutes. Elevation, Analgesics, PRP within 48 hours, MRI within 48 hours if required.

- Manual Therpay

- Cardiovascular: Boxing Steam (anaerobic session, metabolic session, aerobic session), Rope Session (anaerobic session, metabolic session, aerobic session), Bike Session (anaerobic session, metabolic session, aerobic session).

Neuromuscular Control = Lumbopelvic Flexibility.

Hamstring Strengthening

Isometric Stream: Within a controlled symptom free range

- Isometric quad/hamstring holds

- Isometric heel holds

- Prone knee bends

- Nordic hold at 15 degrees

- Single leg prone isometric bar pull (with bands)

Bridging Stream: Within a controlled symptom free range

- Double leg bridge

- DL bridge – hands in air

- SL bridge

- SL bridge hands in air

- Nordic Hold at 15 degrees

Deadlift Stream (to include one set with feet at different width): Within a controlled symptom free range. Speed deadlifting when SL deadlifting

- Hip Hinge

- Kettle bell raise

- Sumo deadlift

- Double leg deadlift

- Stiff leg deadlift

- SL stiff leg deadlift

Squat Stream (to include one set with feet narrow/normal/wide/angular load): Within a controlled symptom free range. Speed Squat when SL squatting

- Banded squat

- Squat (unloaded)

- Loaded squat

- High single leg squat

- Single leg squat

Lengthening: Day 3 post injury, within a controlled symptom free range.

- The extender

- The Diver

- The glider

Lunge Stream: Within a controlled symptom free range

- Split lunge

- Lunge unloaded

- Loaded lunge

- Lunge with twist

- Lunge 360 degree with twist

Jumping Stream: Unload Squat

- Drop squat

- Drop Landing and DL Jump

- Drop Landing with alternate leg land

- Drop Squat with SL hurdle hope

- Drop Squat with multiple hurdle hop.

Running Stream: Unloaded lunge, Day 3 post injury Normal Gait Pattern

- Level 1

- Level 2

- Level 3

- Level 4

Agility Drills: Begins Level 3 SL deadlifting

- E.g. Gaelic Football/Hurling Pickups

- Rugby-Throwing from Ground

Sports Specific Drills: Begins Level 3, SL deadlifting

- E.g. Gaelic Football/Hurling Pickups

- Rugby-Throwing from Ground

Multidirectional: Begins Level 3 Lunge with a twist SL deadlift

- Slalom running

- Cutting

Box Jumping: Begins when drop squats +multiple hurdle hops Sl deadlifting

Level 4 running

- Small box to small box

- Medium box to small box

- Small box to medium box

- Medium box to medium box

Return to Play

- NIL Top

- SSC VU Test

- 100% Straight Line & MD

- Symmetrical HIP ROM

- <10% hamstring strength deficit

- Sports Specific Drills

Here is the protocol in photo format (hence the need to write it out as picture becomes blurry):

My Personal Thoughts on Hamstrings

Now when people come to me saying they have a tight/sore lower back my first thought is their glutes/hamstrings are affecting this. Why? Well if the hamstrings are tight then that’s due to the calves. Hamstrings being tight causes the glutes and hips to be tight as they are being pulled on. This has a knock on effect by making the lower back (erector spinale) aggravated.

This can lead to a pelvic tilt especially if the glutes and lower back are tight. They will be pulled down. It will look like this;

Myofasical release on calves, glutes. Do a dynamic warm up on the trunk and legs. Another thing that could be done to help release tightness is doing a glute/hip activation protocol as shown; https://www.youtube.com/watch?v=vwspH14-D04

Any injury site isn’t the cause it’s the victim of something else

Quick tips

If your knee hurts have your hip & ankle checked out

If you’re hip hurts look at your shoulder and your knee (could be the opposite side not always on the same side).

Assessment of Hamstring Flexibility

Hamstring extension is key to determining flexibility, assessed by performing a sit and reach test. This is a very basic assessment for assessing the flexibility of the hamstrings and lower back (erectors).

All you need is the following;Sit & Reach Box and the Score Chart

Dr David Opar on Hamstring Injuries in Football Players

Dr Opar is a lecturer at the School of Exercise, Australian Catholic University, Melbourne. His focus on hamstring injuries and injury prevention.

One of the studies he looked at was eccentric strength of hamstrings related to age and likelihood of injuries. The older you are and weaker you are eccentrically speaking you are a candidate for a hamstring injury but regardless of age if you keep up a strong eccentric hamstring you have a very slim chance of injury.

When looking at the sport of football/soccer it is the most common injury in the Premier League and accounts for 49.3% of all muscular injuries reported. Yet risk management rather than prevention is the key when it comes to hamstring injuries.

He goes in detail of the Nordic Hamstring exercises

Video in full: https://www.youtube.com/watch?v=3hhMHBg9rOk&list=PL_dU9I9rMcdllJLALCBnEXrDIRmc7dnUu&index=4

A great article by Eamon O’Reily, Senior Performance Rehabiliation Physiotherapist at Sports Surgery Clinic entitled; De-Mystifying Hamstring Injuries.

http://www.sportssurgeryclinic.com/blog-research/blogs-infographics/de-mystifying-hamstring-injuries/542

My 4 Favourite Hamstring Exercises

Nordic Curl, as it’s a great exercise eccentrically but it’s a fantastic for injury prevention. I have all my athletes doing this regardless of sport.

RDL (Romainian Deadlift). Myself being a powerlifter enjoy this as it gets the hamstrings firing in both the concentric and eccentric portions of the lift. More so on the concentric from the floor pulling up it’s a great transfer of strength to the skill of deadlifting.

Video: https://www.youtube.com/watch?v=XowKMitOVNc

Hamstring Curl, simple bodybuilding movement to isolate the hamstring belly. I like to finish off with a few sets of them high reps.

Video: https://www.youtube.com/watch?v=qca__Qgjf1Y

Good Mornings, again like the RDL transfer of strength to the skill of squatting/deadlift is good as it helps maintain upright posture during the lifts whilst training a weaker portion of the movement. The good morning is an exercise to be used in case you end in a bad position during heavy lifting, if you train it well enough you can always recover from it. Now being a bad position isn’t something you should intend to get yourself into.

Video: https://www.youtube.com/watch?v=hllFsZIEuAs

Running Mechanics (relating back to Hamstrings role in running)

What are hamstrings normally used for? While the quads support our body-weight, our hamstrings help us break free from the pull of gravity. When we increase our cadence to 180 or more strides per minute we need hamstrings that are capable of quickly pulling the foot from the ground. However, larger and stronger muscles, trained in static conditions in the gym, do not necessarily translate to better performance when running. The key to developing great hamstrings is performing dynamic drills in order to train the hamstrings.

Some excellent drills are foot tapping and front lunge. Try these drills with stretch cords to increase resistance. The key use of our hamstrings in running is to be able to quickly pull the support foot from the ground.

This was taken from the video Running Technique: Confusion About the Role of Hamstrings in Running: https://www.youtube.com/watch?v=pmyBTespnHc

Juggernaut Program Director, James "The Thinker" Smith, discusses the role different muscles play during different phases of the sprint. We also show you why the GHR is NOT the best option for hamstring training for sprinters and a reverse hyper variation that is superior for hamstring strength and health.

Very good demonstrations, I quite liked using the prowler as a way of demonstrating the running motion.

Video: https://www.youtube.com/watch?v=gikFNVeOmXI

Hamstrings in the Squat

Below is a detailed description (in article, picture and video) of the role of the hamstrings in the squat. Greg Nuckols of Strength Theory has done a great job analysing the role of hamstrings in the squat under 90% 1RM loads. This has brought back some interesting data. What the main areas you will find are the following;

1. In general, the body utilizes single-joint muscles before two-joint muscles really kick in. This makes movement more efficient.

2. At the bottom of the squat, overactive hamstrings make the movement unnecessarily difficult, so squatting in a manner that maximizes hamstrings involvement in the hole is probably unwise.

3. If you find yourself getting pitched forward in the squat, strengthening your glutes helps your hamstrings relax a bit, taking some strain off your quads and making the bottom half of the squat easier.

4. The place you want your hamstrings to kick in is at the sticking point, when demands on the quads have decreased a bit, and the added hip extension torque can help you keep the bar moving.

(4 points take from article as a preview to it).

If you have the time read and watch the content below as it will make more sense as having overactive hamstrings is a bad thing.

Article: http://www.strengtheory.com/hamstrings-the-most-overrated-muscle-for-squat-2-0/

Video: https://www.youtube.com/watch?v=-08XAjzjTUQ

Studies done on Hamstrings looking at injury/emg/force etc

Some good studies done on Hamstrings from three perspectives.

Eccentrics:

- Askling, C., Karlsson, J., & Thorstensson, A. (2003). Hamstring injury occurrence in elite soccer players after preseason strength training with eccentric overload. Scandinavian journal of medicine & science in sports, 13(4), 244-250.

- Jonhagen, S., Nemeth, G., & Eriksson, E. (1994). Hamstring injuries in sprinters the role of concentric and eccentric hamstring muscle strength and flexibility. The American Journal of Sports Medicine, 22(2), 262-266.

EMG:

- Caterisano, A., MOSS, R. E., PELLINGER, T. K., WOODRUFF, K., LEWIS, V. C., BOOTH, W., & KHADRA, T. (2002). The effect of back squat depth on the EMG activity of 4 superficial hip and thigh muscles. The Journal of Strength & Conditioning Research, 16(3), 428-432.

- More, R. C., Karras, B. T., Neiman, R., Fritschy, D., Woo, S. L., & Daniel, D. M. (1993). Hamstrings—an anterior cruciate ligament protagonist An in vitro study. The American journal of sports medicine, 21(2), 231-237.

Force Production

- Ogura, Y., Miyahara, Y., Naito, H., Katamoto, S., & Aoki, J. (2007). Duration of static stretching influences muscle force production in hamstring muscles. The Journal of Strength & Conditioning Research, 21(3), 788-792
- Stanton, P., & Purdam, C. (1989). Hamstring injuries in sprinting—the role of eccentric exercise. Journal of Orthopaedic & Sports Physical Therapy, 10(9), 343-349

I hope you found the article interesting to read. It was heavy at points to read but if you take your time reading it, it will become digestible. It was a very broad article I could have done individual articles on all the sections but I will leave that for another day.

Regards

Andrew Richardson

References

1. Jump up ^ Koulouris G, Connell D. (2003). "Evaluation of the hamstring muscle complex following acute injury". Skeletal Radiol. 32 (10): 582–9. doi:10.1007/s00256-003-0674-5. PMID 12942206.

2. 5.Jump up ^ Schache AG, Koulouris G, Kofoed W, Morris HG, Pandy MG (2008). "Rupture of the conjoint tendon at the proximal musculotendinous junction of the biceps femoris long head: a case report.". Knee Surg Sports Traumatol Arthrosc. 16 (8): 797–802. doi:10.1007/s00167-008-0517-y. PMID 18360748.

3. 6.Jump up ^ Koulouris G, Connell DA, Brukner P, Schneider-Kolsky M. (2007). "Magnetic resonance imaging parameters for assessing risk of recurrent hamstring injuries in elite athletes.". Am J Sports Med. 35 (9): 1500–6. doi:10.1177/0363546507301258. PMID 17426283.

4. Chhajer, Bimal (2006). "Anatomy of Knee". Knee Pain. Fusion Books. pp. 10–1. ISBN 978-81-8419-181-3.

5. Jump up ^ Kulowski, Jacob (July 1932). "Flexion contracture of the knee". The Journal of Bone & Joint Surgery 14 (3): 618–63. Republished as: Kulowski, J (2007). "Flexion contracture of the knee: The mechanics of the muscular contracture and the turnbuckle cast method of treatment; with a review of fifty-five cases. 1932". Clinical orthopaedics and related research 464: 4–10. doi:10.1097/BLO.0b013e31815760ca (inactive 2015-05-08). PMID 17975372.

6. Jump up ^ Rytter, Søren; Egund, Niels; Jensen, Lilli; Bonde, Jens (2009). "Occupational kneeling and radiographic tibiofemoral and patellofemoral osteoarthritis". Journal of Occupational Medicine and Toxicology 4: 19. doi:10.1186/1745-6673-4-19. PMC 2726153. PMID 19594940.

7. Jump up ^ Gill, T. J.; Van De Velde, S. K.; Wing, D. W.; Oh, L. S.; Hosseini, A.; Li, G. (2009). "Tibiofemoral and Patellofemoral Kinematics After Reconstruction of an Isolated Posterior Cruciate Ligament Injury: In Vivo Analysis During Lunge". The American Journal of Sports Medicine 37 (12): 2377–85. doi:10.1177/0363546509341829. PMC 3832057. PMID 19726621.

8. Jump up ^ Scott, Jacob; Lee, Ho; Barsoum, Wael; Van Den Bogert, Antonie J. (2007). "The effect of tibiofemoral loading on proximal tibiofibular joint motion". Journal of Anatomy 211 (5): 647–53. doi:10.1111/j.1469-7580.2007.00803.x. PMC 2375777. PMID 1776452