Injury prevention 101: The quads

The quadriceps is the large muscle group at the front of your thigh. Weakness and/or inflexibility of the quads can lead to a variety of injuries. This article is a summary of the penultimate episode of the Injury Prevention Series. Other topics that I covered in this series included position sense, core stability, glute max, glute med, hamstrings, and calves.

In this article:

• Where are your quads?

• Problems due to a tight Rectus Femoris

  • Hip flexor and quad stretch

• Problems due to a tight Vastus Lateralis

  • How to foam roll your quads

• Injuries due to weak quads

• Strength exercises for the quads

  • Leg press

  • Double leg squat

  • Single leg sit-stand-sit

• Download exercises as PDF

Where are your quads?

Your quadriceps or quads refers to the large group of muscles at the front of your thigh. It is made up of 4 parts:

1. The Rectus Femoris (Rec Fem) runs in the middle of your thigh;

2. The Vastus Lateralis (VL) runs towards the outside of your thigh;

3. The Vastus Medialis (VM) runs more towards the inside of your thigh

4. and the Vastus Intermedius runs between the VL and VM but underneath the Rec Fem

These four muscles come together at the knee and forms the patellar tendon which attaches to the tibial tuberosity. Your kneecap sits inside the patellar tendon. As a group, they work together to extend your knee or to control your knee during bending e.g. when you climb up stairs they help propel you upwards and when you climb down, they control the lowering of your body.

The Rec Fem is the only one that also crosses the front of the hip joint which means that it also helps with hip flexion.

Problems due to a tight Rectus Femoris

The Rec Fem forms part of the hip flexors. Research has shown that tight hip flexors can cause your glutes to switch off. As mentioned before, weak or switched off glutes can contribute to a wide variety of lower limb injuries at the hip, knee and ankle. It is therefore important that you include stretches for the Rec Fem in your regular training programme.

Hip flexor and quad stretch

The main hip flexor muscles are the iliopsoas and rectus femoris. You should stretch both of these.

Purpose: It should be clear from the discussion above that this is extremely important. You will activate your glute max much better if your hip flexors aren’t tight.

Starting position: Half kneel with your one knee on a pillow and your other leg out in front of you. Hold on to something for balance if needed.

Movement: A. Push your hip forward, but at the same time tilt your pelvis backwards. This is important – if you allow your pelvis to tilt forward, the stretch will not be as effective. This will mainly stretch the iliopsoas muscle, but if you’re very tight you may have to spend time on this part first and then add in part B.

1. Once you can easily achieve part A, maintain that position and grab hold of your foot. You may have to loop a belt or towel around your foot if you are very stiff.

Check that: Your pelvis remains tilted backwards throughout the stretch. Remember, strong sustained stretches switches muscles off, so these should be followed by dynamic movements if you're doing them shortly before doing sport.

Aim: Hold the stretch for 30sec and repeat 3 times on each leg.

Problems due to a tight Vastus Lateralis (VL)

Remember that I mentioned that your kneecap sits in the middle of your patellar tendon? All four of the quadriceps muscles attaches to this tendon. If your VL on the outside is tight, it will pull your kneecap slightly out of alignment. Your kneecap is meant to move friction free in its groove, but if the VL is very tight it can cause the kneecap to strain.

The current clinical opinion is that this is one of the causes of patello-femoral pain or runner’s knee. In addition to stretching, you can also use a foam roller to improve the flexibility of your VL.

How to foam roll your quads

In this video I demonstrate how to foam roll your quads.

Injuries due to weak quads

Having strong quads are extremely important if you want to avoid knee pain. Your muscles are meant to absorb significant amounts of the force when you walk. If they aren’t strong, it will increase the strain on your joints. So one of the best ways to protect your knees is to ensure that your quads are very strong.

Not only does it prevent knee strain, but there is also evidence that people with arthritis have less pain and better quality of life if they strengthen their quads. Research in elderly people have also found that people with stronger thigh muscles are less likely to fall.

Weakness in a specific part of the Vastus Medialis, the VMO, has also been found to be one of the causes of patello-femoral pain and is often found in combination with very tight lateral quads (as mentioned above).

Strength exercises for the quads

These exercises may not be right for you and I would suggest that you consult a physiotherapist or other healthcare professional to help you find an exercise that works for you – especially if you suffer with knee pain.

The three exercise below are my favourites, but there are loads of other options available.

The leg press

My favourite exercise to improve quad strength is the leg press machine. I love it because:

• It’s stable and has a very low injury risk for beginners.

• You can really ramp up the weights over time and get good strength gains.

• You can easily do it with one leg at a time and make sure that both legs are equally strong.

I’ve described how to use the leg press (even if you have knee pain) before, so will not go into detail again.

Double leg squat

Purpose: It strengthens your glutes, quads and hamstrings and teaches you good movement patterns for your legs.

Starting position: Standing with feet pointing forwards and spaced hip distance apart.

Movement: Squat down by pushing your bottom out to the back (pretend you want to sit on a chair) and bending your knees. Hold the position for 3 seconds and return to standing upright.

Check that: Your feet stays in a good neutral position. Your knees should move in line with your second toe. Your bottom sticks far out to the back.

Dosage: Start with whatever your knee allows you to do but you should aim to get up to 3 sets of 12 repetitions over time. Rest 2 minutes between the sets.

Once you can easily achieve this progress by replacing it with the single leg sit-stand-sit with.

Single leg sit-stand-sit

Purpose: It’s a great exercise to strengthen your glute med, glute max, quads and position sense.

Starting position: Choose a chair that you can manage to get up from using only one leg. Your aim should be to use a chair that places your knee in 90 degrees flexion, but if this is too hard use a higher surface. I usually place some pillows on the chair to make it easier. Sit on the edge of a chair with your one leg on the floor and the other one in the air. Your hands can either be in your sides or out in front of you.

Movement: Slowly stand up from sitting, using only one leg. Make sure that your pelvis stays level and your knee moves in line with the middle of your foot. Then slowly sit down again.

Check that: Your pelvis and knee stays aligned. If you find that you “plonk” down instead of slowly lowering yourself down, you may have to use a higher chair to start with.

Aim: Test how many your can do with good form from 90 degrees knee flexion. Your aim should be to get to 22 with no wobbling and keeping your pelvis and knee aligned. I can only manage 8 with rather poor form so I should work on the exercise single leg squat with support before doing these. Retest this every 4 weeks to check on your progress.

Start strengthening it by doing sets of 8 reps until fatigue. Rest at least 1 to 2 minutes between sets.

Download these exercises as a PDF

Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.

About the Author

Maryke Louw is a chartered physiotherapist with more than 15 years' experience and a Masters Degree in Sports Injury Management. Follow her on LinkedIn or ResearchGate.

References:

1. Granacher, Urs, et al. "The importance of trunk muscle strength for balance, functional performance, and fall prevention in seniors: a systematic review." Sports Medicine 43.7 (2013): 627-641.

2. Mills M, Frank B, Goto S, et al. Effect of restricted hip flexor muscle length on hip extensor muscle activity and lower extremity biomechanics in college‐aged female soccer players. International Journal of Sports Physical Therapy 2015;10(7):946.

3. Moreland, Julie D., et al. "Muscle weakness and falls in older adults: a systematic review and meta‐analysis." Journal of the American Geriatrics Society 52.7 (2004): 1121-1129.

4. Papadopoulos K, Stasinopoulos D, Ganchev D. A Systematic Review of Reviews in Patellofemoral Pain Syndrome. Exploring the Risk Factors, Diagnostic Tests, Outcome Measurements and Exercise Treatment. The Open Sports Medicine Journal 2015(9):7-17.

5. Witvrouw E, Callaghan MJ, Stefanik JJ, et al. Patellofemoral pain: consensus statement from the 3rd International Patellofemoral Pain Research Retreat held in Vancouver, September 2013. British Journal of Sports Medicine 2014;48(6):411-14. doi: 10.1136/bjsports-2014-093450