The right shoe for the job – is your footwear causing injury?

2 08 2011

Sports Equipment: gender shoe design

 

It doesn’t take a scientist, sports or other, to tell you that men and women are different. However, it was really only recently that kit manufacturers noticed this difference in the area of sports shoe design.


A woman’s foot is 3-4% narrower than men’s – this is particularly manifest  at the rear.


Shoe implications

Manufacturers need to create a specific ‘last’ for their shoes. A last determines the way the shoe is manufactured and the way the relevant pattern making machines are set up.


Women are more prone to getting bunions compared to men


Shoe implications

Some sportswear brands such as adidas incorporate a soft and flexible insert in the shoe’s upper to reduce the friction that could lead to bunions developing.


Women’s feet are more flexible compared to men’s


Shoe implications

Women’s running shoes should be more flexible (but supportive and provide the ‘right’ control of foot-strike – see anthropometrical differences). Often their shoes will have a different tread configuration to allow the female foot to flex in its particular way. For example, in adidas shoes a thinner torsion ™ system bar and additional grooves in mid-foot add to the shoe’s woman-friendly flexibility.

In the illustration below you will see two adidas shoes and their different sole configurations. Notice the pattern (green) on the woman’s (right hand) shoe – this is designed to create greater flexibility.


 



Women’s running style

Women because they are generally lighter than men do not generate such high impact forces – see graph below


 




Women runners exhibit less running forces

 

Because women do not generate as high impact forces as men on foot-strike they require less cushioning in their shoes. This can result in their running shoes having 21% less rear-foot cushioning and 24% forefoot cushioning.

 

Women runners have a different foot-strike compared to men

 

Women strike the ground with a much shallower angle (from heel to toe) compared to men and their feet tend to be less splayed compared to men.  This is known as a ‘less exorated’ landing – putting it into everyday language women’s feet tend to strike the ground with their feet pointing forward at 12 o’clock, whilst men tend to strike the ground at a more ‘10 to 1 o’clock’ position.

Shoe implications:

The different landing foot-strike angles require different heel bevel construction in running shoes. In a woman’s shoe it is more rotated to control their landing – see illustrations below.

Anthropometrical differences

 

The ‘Q angle’

Women’s lower body shape creates greater and different forces on their knees and ankles compared to men. This is largely the result of their wider hips and the inward angle of their thigh bone (the femur which extends from the pelvis to the knee). This is known as the ‘Q angle’.

Greater knee forces

The increased angular forces on the knee also create greater forces on it which could increase injury risk.

 

Running and knee injuries

 

As well as the Q angle other factors such as hamstring and quadriceps muscle flexibility, quadriceps strength, weekly mileage and weight can also influence whether a runner is more predisposed to injury. American researchers evaluated these (and other factors) in 20 runners (13 females and 7 males) ranging in age from 20–55. Specifically they were interested in the extent of the forces that the participant’s knees were subject to whilst running. It’s the often the case that the greater these forces the greater the risk of knee injury. The team discovered that the key factors in terms of increased knee forces were, not surprisingly, greater weekly mileage, poor hamstring flexibility, greater body weight and perhaps less obviously increased quadriceps strength. Greater quadriceps strength needs further explanation as this could be considered a positive and not a negative. In actual fact what matters in particular is the ratio of strength between the hamstrings and the quadriceps. Women tend to have weaker hamstrings when compared to men; this can ‘enhance’ the dominance of the quads in the running action – which due to their anthropomorphic considerations can increase the forces that their knees are subject to. It’s therefore recommended that women (and men) strengthen their hamstrings with relevant weights and body weight exercises (and improve these muscles’ flexibility). In doing so the forces to which the knee is subject can be reduced. Returning to the thoughts of the researchers, they believed that most of these risk factors could be altered to reduce injury potential.

Med Sci Sports Exerc. 2008 Oct 8.

 

Running injuries

Knee injuries are the most common running injuries
Knee overuse 11-49% of running injuries (PFPS is the most common running overuse injury)
Shin splints 5-20%
Achilles tendonitis 2-18%
Plantar fasciitis 2-14%
Stress fractures 2-16%
Illiotibial band syndrome 4-10%

Source: University of Calgary

PFPS (patellofemoral pain syndrome) is more commonly known as ‘runner’s knee’. Pain is normally felt on the outside of the knee and comes on after 20 minutes of running

 

Implications for shoes

Women tend to run with an over-pronated gait.  Over-pronation means that the foot turns too much inward on foot-strike from the body’s centre line. This means that, depending on the degree of pronation, a shoe needs to be either a motion control or a support one. Pronation can lead to an increased injury risk.

Shoes can be designed to reduce the forces that the knees are subject to – for example adidas shoes have a technology called ‘formotion™’  – which is positioned at the heel which control pronation and therefore knee loading.

As can be seen from the above research and information, it is definitely not a case of ‘one size fits all’ when it comes to choosing the right running shoes based on your gender. There are myriad factors that that make the requirements of women’s shoes different to men’s and shoe companies are investing heavily in relevant technologies and research.


Advertisements




The Care and Prevention of Achilles Tendon Injuries Part 2

28 06 2011

DIAGNOSIS

A detailed history, and examination by an appropriately qualified health professional, will allow a diagnosis to be made. An ultrasound or MRI scan can confirm the diagnosis.

Other causes of symptoms in the area, such as those referred from the lumbar spine and local infection, should be excluded.

 

PREVENTION

Training

Good flexibility of the calf muscles plays an essential role in the prevention of Achilles tendon injuries.

 

It is also important to include balance and stability work as part of the training programme. This should include work for the deep-seated abdominal muscles and for the muscles that control the hip. This might at first appear odd, given the fact that the Achilles are a good distance from these areas, but developing strength and control in this area (core stability) can boost control at the knee and ankle joints.

Training errors should be avoided. The volume, intensity and frequency of training should be monitored carefully, and gradually progressed, particularly when introducing new modes of training to the programme. Abrupt changes in training load are the primary cause of Achilles tendinopathy.

Footwear and training advice

I have found that, when track athletes (particularly sprinters), run over-distance repetitions (for example, 300m) as part of their training, the Achilles is subject to great forces, as the athlete tires and their heel drops further during each ground contact. This can be counteracted by purchasing a pair of middle-distance-type spike shoes that have a protective heel wedge. This reduces the strain on the tendon, as the shoe’s heel offers greater protection, and is not subject to overstretching when fatigue is present. I also advocate that any running below 90% of maximum speed is performed in trainers and preferably on a stable grass surface.

Very often sports people wait until their sports footwear (trainers/boots/spike) are well beyond the state at which they provide adequate protection and support before replacing them. Then, after an injury has occurred, they are advised by a physiotherapist and/or coach to buy a new pair. Trust me, it is cheaper to buy sports footwear regularly and stay healthy, than to pay for physiotherapy treatment (and buy the necessary footwear).

ACHILLES TENDON INJURY TREATMENT

Ice therapy is an effective form of pain relief. Observe the PRICE protocol:

PROTECTION

REST

ICE

COMPRESSION

ELEVATION

This can relieve the symptoms of a painful swollen Achilles tendon. Using ice packs for a period of 20 minutes every two hours can help with the swelling and pain, but pain relieving medication may also be required.

It may be necessary, in severe cases, to rest from high-impact activities for up to three months. This is because the collagen tissue, which the body produces to repair the damaged Achilles tendon tissue, can take three months to lay down.

Non-impact training, such as pool work, can maintain fitness during this period, and other body parts can be exercised with weights or other exercises. A physiotherapist may gently mobilise the soft tissue by providing controlled stress to help the tendon adapt and gain tensile strength.

Published research has suggested that recovery is promoted by using a very gradually progressed strengthening programme for the Achilles tendon and calf muscles under the supervision of a sports specialist/therapist/Physiotherapist. This strengthening programme uses eccentric muscle work, which means that the muscle is lengthening while contracting. Maximum tension is generated in the muscle and tendon during eccentric contractions.

Biomechanics

It is important that an appropriately qualified therapist looks at the players’/athletes’ overall body alignment to detect if the injury has been caused by a biomechanical problem. Over pronation can place excessive strain on the Achilles and lead to Achilles tendinopathy. An orthotic insert may be required but, in many cases, biomechanical problems are caused by stiffness in the joints. The therapist can mobilise them, which, if normal range of movement is attained and maintained, can often eradicate the problem.






The Care and Prevention of Achilles Tendon Injuries Part 1

28 06 2011

What is the Achilles tendon?

The Achilles tendon is situated above the heel and forms the lower part of the calf muscles. It is a continuation of the two calf muscles, the gastrocnemius and soleus muscles, and it attaches to the heel bone.

It is the strongest tendon in the human body and must withstand great forces. Its function is to transmit the force produced by the calf muscles to lift the heel and produce the push off during walking, running and jumping. The Achilles can produce force of up to seven times body weight. This shows just how much force it has to withstand during sporting activities, such as sprinting, jumping and turning.

Understanding terms for Achilles tendon injury

Achilles tendinopathy is a common sports injury. It’s caused most frequently by overuse. You might be more familiar with the term ‘Achilles tendonitis’. However, in the absence of inflammation, tendinopathy is the more appropriate term.

Until medical examination determines if there is Achilles degeneration (tendonosis) or inflammation (tendonitis) the condition is referred to as tendinopathy.

Achilles tendinopathy is characterised by degeneration (tendonosis) of the tendon, often without an inflammatory response. The degeneration means that the tendon does not have the usual tensile strength and may be liable to rupture during continued sporting activity. However, before you get alarmed, this is very unlikely.

SIGNS AND SYMPTOMS

  • Symptoms usually come on gradually. Depending on the severity of the injury, they can include:
  • Achilles pain, which increases with specific activity, with local tenderness to touch.
  • A sensation that the tendon is grating or cracking when moved.
  • Swelling, heat or redness around the area.
  • The affected tendon area may appear thicker in comparison to the unaffected side.
  • There may be weakness when trying to push up on to the toes.
  • The tendon can feel very stiff first thing in the morning (care should be taken when getting out of bed and when making the first few steps around the house).
  • A distinct gap in the line of the tendon (partial tear).

The causes of Achilles tendon injuries

Overuse and changes in training

Inflammation/strain of the tendon is usually caused by overuse – for example, frequent jumping in volleyball, netball or basketball. It is often also caused by a sudden increase in certain types of training, such as hill sprinting or track running, particularly when running in spikes.

Getting older

Tendinopathy can also be associated with ageing. Our ability to regenerate damaged tissue decreases as we age and the quality of the tendon deteriorates. However, the better news is that sensible training can actually strengthen all our soft tissue (tendons, ligaments and muscle).

Tight calf muscles

Tightness in the calf muscles will demand greater flexibility of the tendon, which inevitably results in overuse and injury. Biomechanically, the tightness can reduce the range of dorsiflexion (toe up position) in the ankle, which increases the amount and duration of pronation. This problem is known as overpronation.* This reduces the ability of the foot to become a rigid lever at push off and places more lateral and linear forces through the tendon. This imbalance can translate into altered rotation of the tibia (shin bone) at the knee joint and, in turn, produce compensatory rotation at the hip joint with subsequent injuries to the shin, knee and hip.

Lack of ankle stability

Lack of stability around the ankle joint can also be a contributory factor, as recurrent ankle sprains appear to be associated with a high incidence of Achilles tendonopathy.

Wearing the ‘wrong’ shoes

Wearing shoes that don’t fit or support the foot properly can be a major contributing cause of Achilles tendon injury.





Delicious & easy recipe, try it out!

23 06 2011

Spinach, Sweet Potato and Cherry Tomato Frittata
 
Serves 1-2
 
Ingredients
 
For the frittata
 
2 tbsp olive oil
½ onion, finely chopped
2 handfuls baby spinach leaves
8 whole cherry tomatoes, halved
½ medium sweet potato, peeled and cut into chunks (65g)
3 medium free-range eggs, beaten
salt and freshly ground black pepper
 
For the salsa verde
 
1 handful fresh parsley
1 handful fresh basil
1 garlic clove, crushed
2 tbsp olive oil
½ lemon, zest only
3 canned anchovies, drained and chopped
 
Preparation method
 
1. Preheat the oven to 180C/350F/Gas 4.
2. For the frittata, heat the olive oil in an ovenproof frying pan and gently fry the onion for 2-3 minutes, or until softened. Add the spinach, cherry tomatoes and sweet potato and continue to fry for a further 3-4 minutes or until the sweet potato is just becoming tender.
3. Pour in the eggs, season well with salt and freshly ground black pepper and cook for 1-2 minutes, or until the egg starts to set around the edges. Transfer to the oven for 2-3 minutes, or until the egg is just set. Remove from the oven, slide onto a serving plate and cut into wedges. Keep warm.
4. For the salsa verde, place all of the salsa verde ingredients into a food processor and blend until smooth.
5. To serve, drizzle the salsa verde around the edges of the plate.
 





Vibration Training – Does it give the results the experts claim?

20 06 2011

Vibration training has become increasingly popular with athletes and, much more recently, everyday fitness trainers.

How did vibration training come about?

Vibration training was developed by the Soviets in response to their space programme. Specifically, to keep cosmonauts in space in as best physical condition as possible for the longest period of time. The USSR held numerous endurance records in this respect.
 
How does vibration training work?

Vibration training uses specially designed ‘gym’ machines that vibrate at frequencies normally between 30-50 Hz. The main example is ‘platform-based’ – although there are also vibration dumbbells, and even breathing devices (to strengthen the breathing muscles).
 
More specifically, it is argued that…

Vibration training can recruit nearly 100% of a muscle’s/muscle groups’ muscle fibres. This contrasts with the 40-60% recruitment normally associated with other resistance training activities.
 
How does it recruit so much muscle fibre?

Vibration training achieves these high recruitment levels by creating an almost continuous muscle contraction. Specifically, this is called a ‘tonic stretch/reflex’ and means that, while subject to vibration training, your muscles are automatically contracting at incredibly high frequencies. And they are also subject to considerable force – at 30Hz the body is subject to a load equivalent to 2.5 times its weight.
 
Increased blood flow

Vibration training also stimulates increased blood flow to the muscles. This can speed up recovery from work outs and rehabilitation from injury.
 
Better balance

Due to vibration, balance and body awareness are believed to be enhanced.
 
Other applications

I also found out that vibration training has developed credence within the medical world where it is used for the treatment of, for example, cerebral palsy, osteoporosis, chronic pain and back injuries.

Research
I looked at some research to discover what the sports scientists really think of vibration training. After all, you can’t believe all the hype the manufacturers might make. In trawling through the learned journals and talking to vibration experts I found out, for example, that not all machines work the same, which can make comparisons difficult and apparently alter the efficacy of the specific machines.
 
Whole-body vibration training

Roman researchers looked at the effects of whole-body vibration training on various measures of physical performance in female competitive athletes – whole-body vibration requires the athlete to stand on the vibration machine plate for designated time spans and/or perform reps of designated exercises, with or without added resistance (2). The athletes were split between a vibration group (13 athletes) and a control group (11 athletes). The former vibration group trained three times a week. At the end of this period they were tested on:
counter-movement jump (bend the knees, extend and jump) 
leg extension strength  
horizontal leg press  
flexibility – sit and reach test.
Watch video of these exercises being demonstrated

The researchers found that the vibration trainers displayed a significant improvement in leg extension strength, counter-movement jump performance and flexibility. There were no significant changes in the tested abilities of the controls. The team qualified their findings by indicating that the optimal frequency, amplitude (movement of the vibration platform), and g-forces need to be identified when using vibration training in order to maximise its effects.
 
I then discovered that transatlantic research between the University of Aberdeen and the University of North Dakota discovered that a 30Hz protocol with 10mm amplitude (the travel of the vibration plate) for their 60 seconds on/off of vibration training exercise protocol, elicited the most significant muscle fibre recruitment in the vastus lateralis (thigh muscle) as measured by EMG (electrical activity in muscles)(1). Higher frequencies did not elicit a significantly superior response. The athletes – in this case elite female volleyball players – stood on the platform in a squat position with their knees at a 100-degree angle.

Everyday fitness and aerobic development with vibration machines…

I then wanted to find out whether vibration training could work for the fitness population. As I said at the start of this piece, many commercial gyms are installing vibration machines and many home models are entering the market.
Belgian researchers compared the effects of whole-body vibration training for fitness purposes on untrained women (3). What makes this research particularly intriguing is the fact that aerobic training was also included in the design – I’d assumed that vibration training was predominately a resistance training method. In this instance they wanted to see whether vibration work outs could reduce body fat – this is something that would normally be associated with CV training.

Forty-eight untrained young women (average age 21) were involved in the study. The whole-body vibration group (18 members) performed unloaded static and dynamic exercises on a vibration platform. The fitness group (also 18 members) followed a standard cardiovascular (15-40 minute duration) and resistance training programme. The latter included the leg press and leg extension exercises. Both groups trained three times a week. There was also a non-exercising control group (12 members). The researchers measured body composition by underwater weighing and took 12 skinfold measurements to measure body fat levels. Quadriceps strength was also tested.

The results: over the 24-week progamme, there were no significant changes in weight, in percentage body fat, nor in skinfold thickness in any of the groups. However, fat-free mass increased significantly in the whole-body vibration group only. I believe this could be explained by the fact that they’d increased their muscle mass, probably because of the vibration training’s ability to target increased amounts of muscle fibre. The more muscle you have, the leaner you will tend to be due to this body tissue’s high metabolic cost.

Additionally, the vibration trainers also benefited from a significant strength increase, as did the fitness group. This led the researchers to conclude that, ‘The gain in strength (for the vibration training protocol) is comparable to the strength increase following a standard fitness training programme consisting of cardiovascular and resistance training.’

Interesting results, indeed, for the proponents of vibration training for fitness purposes.
Conclusion
It seems from the research quoted that whole-body vibration training can enhance (or at least match) performance in sport and fitness activities achieved by ‘normal’ training methods. Richard from Galileo did say that whole-body vibration training should be regarded as an adjunct to your normal training and not as a wonder work out.

For more information or to book a vibration training session get in touch with the fitness specialist at info@the-fitness-specialist.co.uk or call 07867 535696.





Nutrition and Supplements – Protein

19 06 2011

This week, I thought we’d take a look at protein. There’s a lot of nonsense pedalled about protein, particularly by companies trying to flog supplements, so I thought I’d try to clear some of the murky waters – at least in part.

What is protein?

Proteins form the major building blocks of muscle and other tissues within the body, as well as hormones, enzymes and haemoglobin in the blood. They are composed of subunits called amino acids. There are about 20 amino acids that we know of. 12 of these are made by our bodies; the rest we need to get through our diet and they’re what we call essential amino acids. If we don’t get these through our diet, the ability of our muscles to grow or recover from training is compromised.

How much do we need?

“It’s important to remember that supplements don’t provide everything a healthy balanced meal can and so they shouldn’t replace meals on a long-term basis.”
This is an area of considerable debate. Strength athletes need between 1.6 – 2g per kg of body weight per day. For an 80kg athlete, this means they may need around 130 – 160g of protein. Endurance athletes need protein in their diets as well, to ensure muscle mass is not lost following training, but they need less (around 1.2 – 1.6g).

Many bodybuilders maintain that they need considerably more than this and I’ve seen reports of people taking 6g per kg of body weight. They cut down on their carbohydrates to remain very lean and so it’s likely that the extra protein they consume is utilised as a fuel source, albeit an inefficient one.

Do we need supplements?

I advocate the use of supplements in my job. The reason is because I want to provide nutritional support to the training athlete within half an hour of them finishing a training session. Using a protein shake is a convenient method to ensure that we hit our protein targets within this crucial 30-minute window. Equally, though, a protein-rich meal is just as good, if not better, than a shake; it’s just that this option is not always feasible in our environment and not everyone feels like a meal so soon after training.

Downsides and alternatives

It’s important to remember that supplements don’t provide everything a healthy balanced meal can and so they shouldn’t replace meals on a long-term basis. There is also the risk of a contaminated batch, which can be problematic if you or your athlete is subject to drug testing. You always need to make sure that your supplements come from a reputable source, preferably one that has independent batch testing. Finally, they can be expensive. Believe it or not, the same basic job can be done by consuming a boiled egg and chocolate milkshake! It has the carbohydrates necessary to get an insulin response (necessary for the release of growth hormone) and the milk and egg also provide the protein you need.





Spicy Thai prawn noodles

17 06 2011

 
 
Spicy Thai prawn noodles
 
Ingredients
 
200g/7oz Thai rice
noodles
1 tbsp sesame oil
2 eggs, beaten
1 red chilli, finely
chopped
1 thumb-size piece
ginger, grated
450g/1lb peeled cooked
Atlantic prawns
1 tbsp soy sauce
small bunch coriander,
roughly chopped
½ small bunch mint,
roughly chopped
zest and juice 1 lime
small handful roasted
peanuts, chopped
 
Preparation method
 
1. Cook the noodles following the pack
instructions, drain and set aside for later.
2. Heat the oil in a large frying pan and pour
in the beaten egg. Swirl around the pan to
make a thin omelette, cook for 1-2 mins,
then flip over and cook the other side for
1 min. Tip out and slice into thin strips.
3. Add the chilli and ginger to the pan,
fry for 1-2 mins then tip in the noodles,
prawns and egg.
4. Splash in the soy sauce
and stir-fry for 1 min more. Throw in the
chopped herbs and pour over the lime
juice and zest, then sprinkle over the
chopped peanuts and serve.
 
 
SERVES 4 • PREP 15 mins • COOK 15 mins
PER SERVING 385 kcals, protein 34g, carbs 42g, fat 11g, sat fat 2g, fibre 1g, sugar 1g, salt 2.80g