Unstable Knees? 5 Important Exercises That Really Help.
Do you have knees that give way or cave in? Do you experience popping, locking or clicking sensations? Have you noticed frequent pain or an inability to straighten out your knee? You may be suffering from knee instability!
Unstable knees are caused by a variety of reasons including osteoarthritis, trauma, injured ligaments but more commonly muscle imbalances.
The knees rely heavily on the surrounding ligaments and musculature for support therefore they need to be strong and healthy to adequately stabilise the knee during movement.
There are five major muscle groups of the leg;
- Glutes (gluteus maximus, medius and minimus)
- Quadriceps (rectus femoris, vastus medialis oblique (VMO), lateralis and intermedius)
- Hamstrings (semimembranosus, biceps femoris and semitendinosus)
- Adductors (Adductor magnus, longus and brevis, pectineus and gracilis)
- Calves (gastrocnemius).
The glute muscles are responsible for the extension of your leg. The occurrence of decreased muscle activity in the gluteus medius muscle can cause adduction and internal rotation of the hip joint, forcing the knee to cave inward also known as knee valgus. (Kim, 2016).
Over time this weakness in the gluteus medius causes overactivity and shortening in both the Iliotibial band (ITB) and tensor fasciae latae (TFL) leading to lateral knee instability.
Due to the lack of stability, degeneration may occur within the ankle or hip joints as they gradually become overloaded which highlights the importance of building gluteus muscle strength.
The Glute Bridge is a great exercise to begin with.
Instructions: Lay on your back with your feet under your knees, find a neutral spine posture and brace your abdominal muscles. Squeeze the glute muscles and slowly raise the pelvis. Hold the pelvis up for 1 to 3 seconds, lower down and repeat. (Figure .1)
The Step Up exercise elicits the highest levels of gluteus maximus activation but is also great for your quads, hamstrings and core.
Instructions: Start by standing hip-width apart with your toes pointing forward. Allow 2-3 inches between the front of your foot and the step. Lift one foot and place it onto the step, (ensuring your whole foot is on the step and aligned with the knee and hip). Use the front leg to drive you up whilst keeping your body in an upright position. Once you’re standing on the step, lower yourself back down in a controlled way with the back foot. (Figure .2)
The Step Up exercise elicits the highest levels of gluteus maximus activation but is also great for your quads, hamstrings and core.
Instructions: Start by standing hip-width apart with your toes pointing forward. Allow 2-3 inches between the front of your foot and the step. Lift one foot and place it onto the step, (ensuring your whole foot is on the step and aligned with the knee and hip). Use the front leg to drive you up whilst keeping your body in an upright position. Once you’re standing on the step, lower yourself back down in a controlled way with the back foot. (Figure .2)
All four quadriceps muscles attach to the kneecap via a tendon which also connects to the shin bone (tibia). These muscles enable the hip joint to flex and the knee joint to extend.
When these muscles demonstrate weakness, the force, load and stress placed onto the knee are unable to be transferred and absorbed by the quad muscles efficiently. This creates abnormal loading patterns and therefore damages the structures that make up the knee such as the cartilage, menisci, ligaments and bones. (Herzog, Longino and Clark, 2003).
Compound exercises are very effective when increasing the strength of these muscles and stability of the knees as they recruit multiple muscles simultaneously (Escamilla, 2001).
Two compound exercises to include in your knee rehabilitation or stability routine are squats and single-leg deadlifts.
The Squat is present in many of your everyday activities such as climbing up and downstairs, walking, sitting, and standing. It has many benefits including improving joint health, increasing flexibility, entire body strength and preventing medial or lateral displacement on the knee. (Lorenzetti et al., 2018).
Squats specifically target the quadriceps (activated within 0-90° of knee flexion) and the gluteus maximus (which is activated once the body lowers to 90° of knee flexion).
Note; Training squats between 0-50° are appropriate for many knee rehabilitation cases as it reduces the amount of force applied to the knee (Escamilla, 2001).
Instructions: You can use your bodyweight or place a barbell on the trapezius muscle and hold it with a comfortable hand position. Stand with your feet hip-width apart. Keep the heel and the second toe aligned. Keep your back straight throughout the movements. Perform the squat at the same speed in the downward and upward movements. Lower your body, bringing your thigh parallel to the floor.
Note: During the squat, if the calf muscles are tight or the adductor are overworking, the knee is likely to track inward. Try a squatting variation with a heel lift or increase the ankle strength to reduce the medial knee displacement.
The Single-Leg Deadlift is a hamstring dominant, hip-hinge exercise aimed at strengthening the lower back, hips, knees and ankles. It significantly improves balance and reduces the risk of injury to the knees.
Instructions: Use your bodyweight or place a weight in the opposite hand to the front foot. Stabilise your front foot on the ground, (evenly distribute the weight across the toes and the heel). Slowly kick the other leg back as you lean your torso forward, hinging at the hips. Keep the back toes facing down to avoid rotating the pelvis outward. Maintain a slight bend in the front knee. Lower the weight just below the knee and return to the upright position, bringing your back leg to the ground.
Last but not least, an excellent exercise for increasing the strength within the vastus medialis oblique (VMO) and knee, The Peterson Step. This is a technical exercise with the balance being an important component.
Instructions: Start by placing your working leg sideways onto an elevated platform (10-15cm).
Ensure the heel of the supporting leg lines up with the toes of your working leg. (You will have a slight bend in your working leg for the moment). Raise the toes of the supporting leg to prevent pushing off with this leg and raise the heel of the working leg as high as possible. As you push up with the working leg you will lower the heel, then raise the heel again before lowering the support leg back down whilst maintaining the raised toe position.
For visual learners, a great video to watch is;
https://www.youtube.com/watch?v=sDKT6P-ajis
With 5 important exercises to help you gradually build your knee strength and stability, you’ll be back to what you love to do in no time; whether that’s running 10K’s, heading into the netball and football season or walking the dogs.
Your muscle health, pre-hab and rehabilitation are key components for the successful prevention of and recovery from injury and disease (Herzog, Longino and Clark, 2003).
If you require further assistance with any of these exercises, don’t hesitate to ask the Chiropractors at Sims and Finn Chiropractic!
What to do next?
It is important that you obtain an accurate diagnosis before commencing any form of therapy.
A thorough examination by a Chiropractor and another health professional will help investigate the cause of symptoms through neurological testing, orthopaedic testing, muscle strength examination, physical examination and/or other diagnostic modalities.
We will then provide you with the best course of action whether it is Chiropractic care, exercises or referral to your local medical practitioner.
References:
Kim, E., 2016. The effect of gluteus medius strengthening on the knee joint function score and pain in meniscal surgery patients. Journal of Physical Therapy Science, [online] 28(10), pp.2751-2753. Available at: <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5088119/> [Accessed 26 March 2022].
Herzog, W., Longino, D. and Clark, A., 2003. The role of muscles in joint adaptation and degeneration. Langenbeck’s Archives of Surgery, 388(5), pp.305-315.
ESCAMILLA, R., 2001. Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise, pp.127-141.
Paoli, A., Gentil, P., Moro, T., Marcolin, G. and Bianco, A., 2017. Resistance Training with Single vs. Multi-joint Exercises at Equal Total Load Volume: Effects on Body Composition, Cardiorespiratory Fitness, and Muscle Strength. Frontiers in Physiology, 8.
Lorenzetti, S., Ostermann, M., Zeidler, F., Zimmer, P., Jentsch, L., List, R., Taylor, W. and Schellenberg, F., 2018. How to squat? Effects of various stance widths, foot placement angles and level of experience on knee, hip and trunk motion and loading. BMC Sports Science, Medicine and Rehabilitation, 10(1).