Exercises to Strengthen the Knees

Knee injuries have been found to correlate with a reduction in neuromuscular control when performing movements that are high risk from a biomechanical standpoint (Achenbach et al. 2017, Hadzvic et al. 2020, Kristinaslund et al. 2012, and Krutsch 2019 and Saunders et al. 2012).  Common movement patterns associated with knee injury include sport specific patterns including cutting, lateral movements and pivoting. If there is a lag (a hundredth of a second), between the movement and the neurological system activation, an instability can occur around a joint resulting in injury (Ball 2019).  This disconnect can exist due to a number of factors: previous injury, pain, inflammation, poor proprioception, joint laxity among others (Risberg et al. 2001).

Studies have found that neuromuscular training in addition to proprioception, balance, strength, core, agility and plyometrics combine to help reduce sports related injury (Clausen et al. 2017, Stricker et al. 2020).  Neuromuscular exercise is a training method with the aim to improve quality of movement.It is defined by Dr. Michele LaBotz as a way to teach the nerves how to make the muscles work in a way that is consistent with best performance and lower injury risk (“TrueSport” 2020). Neuromuscular training is a combination of different elements including functional performance, postural control, muscular strength, balance and functional stability.  When starting a training program it is advisable to start with closed kinetic exercises (where the limb is in contact with a surface) and progress to an open chain exercise (jumping).   Form and technique are important considerations to ensure progression and not the acquisition of further injury.  

Exercise selection will depend on the age and skill level of the individual.  The addition of external weight or addition of other equipment may not be appropriate for all (Sticker et al. 2020).  Starting with bodyweight exercises and progressing to include external weights (if appropriate), is advisable regardless of level.  As with any exercise program it's important to have a balance between training and rest (Stricker et al. 2020).  As many of the exercises associated with neuromuscular training are plyometrics and explosive in nature, overtraining is a risk due to greater energy output.  It is recommended that exercises are performed in front of a mirror and with the supervision of a trainer or exercise specialist, particularly in the beginning to ensure proper progression and technique (Stricker et al, 2020, “TrueSport” 2020).  

EXERCISES

Below are examples of neuromuscular training exercises that can be added to your current exercise routine.  Please see your healthcare provider before modifying or starting a new exercise program.  The exercises associated with neuromuscular activation can be strenuous in nature and can be challenging for the cardiovascular system.  If you have any cardiac issues please consult your physician.  All of these exercises should be performed in front of a mirror under supervision, videoing can also help you examine and improve your form. 

PLYOMETRIC EXERCISES 

Jump squats 

Stand with feet hip width apart, toes pointed outward slightly.  Bend your knees and sit your hips back like you are going to sit in a chair, and pull your arms behind you, with your hands by your hips.  Explode upward, pushing away from the ground to go as high as you can, body and legs in a straight line.  Land by rolling through your foot, ball, mid, heel, bending the knees and sitting back in sequential order to absorb the impact, as you come back into the bent knee starting position.  You can repeat for 8-12 reps, for 1-3 sets, stop if your form starts to fail.  

Tuck Squats

Stand with your feet hip width apart, toes pointed slightly outwards. Bend your knees and sit with your hips back, and pull your arms back with your hands by your sides.  Explode upward, keeping your torso upright.  Pull your knees up to bend at 90 degrees at the top of the jump, then extend them below your torso as you start to descend.   Land by rolling through the foot (ball, mid, then heel), bending the knees and sitting back in sequential order to absorb the impact, and come back into the bent knee starting position.  

Try 8-12 reps, for 1-3 sets, stop if your form starts to fail.  

Split Squat

Standing with a staggered stance, one foot in front of the other while keeping feet hip width apart.  Bend both knees, dropping your hips between your knees.  Keep the front heel on the ground and lift the back heel off of the ground.  Scissor your arms with the front arm in opposition to your front leg.  Explode upward, straightening your legs and switching your arms, try to jump as high as you can.  Land by rolling through your front foot, ball, mid, heel, bending the knees.  For your back foot you will be landing on the ball of the foot, you will want your weight mostly on the front leg.  Try to absorb as much impact by bending your knees as possible.   Complete all reps with one leg before switching to the other side.  

Try for 8-12 reps, for 1-3 sets, stop if your form starts to fail.  

Triple Hop

Standing on one foot, bound as far forward as you can on one foot three times, holding the last landing to challenge your balance and proprioception.  Land each hop by sitting your hips back and bending your knee, lastly roll through your toe, mid foot and heel and quickly transfer your weight, helping you to absorb impact and maintain balance. You can scissor the arms to help stabilize your body and to help create momentum to move forward.  Keep your weight forward and over the working leg to help you maintain your balance.  Try to be aware of your landing leg and knee, don’t let the knee collapse inward or outward upon landing.  Repeat on the other side.

Try 1-4 sets on both sides, stop if your form starts to fail. 

Single and Double Leg Bounds Forward to Back,  Side-to-Side and Angled

Apply tape in a cross on the floor to make 4 spaces. 

Standing in the middle of the tape, hop forward, back, side-to-side, or at an angle at random.  It may be best to do a clockwise followed by a counterclockwise pattern if you are new to the exercise and master forward/back and side-to-side before incorporating angle bounds.  This exercise can be done with one or two legs.  You can choose to hit the end of the tape for straight lines or angle into the boxes, returning to the center between.  Try to keep your head and torso upward with movements being quick and light.  Be aware of your form, try to keep the knee stable.  As this exercise requires quick bounding movements, try to stay relaxed and bend the knees and keep low throughout the exercise.  To prevent imbalances try to alternate sides for  repetitions and sets.  This exercise is well suited as a timed exercise.  

Try 30 seconds on 30 seconds off, stop if form starts to fail in any direction.

Single Leg to Double Leg Land and Hold

Start standing on both legs, feet hip width apart, bound forward from two legs onto one leg, bound forward again from one leg and land on two feet.  Hold your final landing before going back to the starting position or turning around to do so again.   Try to bend the knee and sit back in the hips as much as possible in addition to landing from toe-to-heel to reduce impact.  

Try 1-4 times for each leg alternating between each set.

Scissor Jumps

Start standing on two legs, hip width apart, bend knees and push hips back into a squat.  Scissor arms one forward and one going back hand behind hip while keeping chest facing forward and out.  Push off the ground with both legs jumping into the air and scissor the legs at the peak.  Bring both legs back under the torso to land.  Transfer the weight through the toes, mid foot, heels, bend the knees and sit the hips back in sequence. Using the arms in opposition will help you maintain balance in the air and can help you generate power.  Repeat on the same side for time, 30 seconds on 30 seconds off.  Then switch sides.

Lateral Jump Over Object

Stand to one side of a cone, broom or other object on one or two legs.  Bound sideways over the object of choice, being sure to get high enough and bend your knees to fully clear the item.  Try to control the torso and keep your arms by your side, so as not to lose momentum.  Land softly to absorb impact rolling from the balls of the foot, through the mid foot, to heels, knees then sit hips back, push back through the heels to return to the start.  This is a great timed exercise.

Try 30 seconds on 30 seconds off, stop top if your form starts to fail.

Ladder Speed Drills

You will require a speed ladder for this exercise.  There are a number of different patterns and drills.  Some common patterns are grape vine, in and out, among others.  You can Google different speed ladder drills online.  Always work to keep an upright posture, breath throughout the drill, and focus on form over speed while you are still learning.  Once you have a hang of the foot pattern you can work to increase your speed.  Working from the ball of the foot, keeping the knees bent and the body low can help to increase speed, balance and agility for these kinds of exercises. 

https://fitnesshealth.co/blogs/speed-training/40956932-10-best-speed-ladder-drills-for-soccer, April 2016

Skipping Rope

Skipping rope is an excellent exercise for agility, and endurance.  It is not a great exercise for those who cannot tolerate high impact exercises.  Skipping can be performed as a warm up or a way to intersperse with other training styles, or it can also be used on its own.   Different foot drills can be performed including single leg, double leg, single leg to double leg, cross rope and double unders.  Focus on breathing while performing the activity, ensure upright relaxed posture, with the weight predominantly on the forefoot to assist with speed and not catching the rope.  Keep the legs under your pelvis while in the air, making sure your bound has enough height to allow the rope to clear the feet.  Upon landing, bend the knees to help absorb impact.  You want to try to keep your grip symmetrical on the handles while keeping the shoulders relaxed.  

Try for 30 seconds continuous skipping and progress to several minutes if desired.

BALANCE EXERCISES

Balance Exercises, Single and Double Leg

Balance is often taken for granted but it’s something that should be practiced.  Double leg balance is the easiest type of balance.  It can be performed barefoot or with shoes, on a solid surface, a mat, a foam pad or on a balance board.  When practicing balance you always want to keep your head up and your eyes fixed forward.  There are a few parameters that you can work with to challenge your balance.  Your stance (wide, narrow or tandem, double or single leg stance), your eyes (open or closed), head position (looking in different directions), and the surface you are standing on (foam, balance board, solid surface, shoes, or barefoot).  

Always start in a clear area away from clutter near a counter or stable surface which you can use to help you stabilize yourself.   To progress you can start with a wide stance, eyes open on a stable surface in front of you while standing on a stable surface.  When you feel stable, with minimal sway you can start to progress, pick one variable to change.  For example try to close your eyes and see if you start to lose balance, if not then you open your eyes and narrow your stance, if this feels good then you can switch to closing your eyes.  

For an additional challenge you can change your head position once you have mastered a forward facing upright head position.   Balance boards and foam give you the opportunity to challenge your balance in different ways.  There are a multitude of boards that can be selected to suit your specific skill level and needs, be sure to work with equipment that is appropriate for your current skill set.  

Multi Directional Ball Roll

Standing on one leg, place a small ball or a Pilates ball under your foot.  With control, roll the ball out in front of you with your foot, resist the temptation to apply too much body weight to the ball.  Once you have reached an extended position you can roll the ball back to the starting position.  Repeat going to the side and back.  Try to keep the pelvis level, with the core and glutes engaged through the movement.  This exercise is to challenge your balance so try to sustain an upright posture with a relaxed supporting leg and your hands on your hips or by your sides.  If you don’t have a ball, this exercise can be done with slide discs or a cloth.

Try 8-12 repetitions in all directions one one leg before switching sides, 2-3 sets.

 

STRENGTHENING EXERCISES

Nordic Strains

Kneeling on a foam, mat or other protective surface, hook your feet under a solid object like a couch or have someone brace your feet while you are in a tall kneeling position.  Have your arms ready to catch your body, and with control lower your torso towards the floor in a straight line.  Try to keep the movement as controlled as possible and refrain from flexing forward at the hips.  If you have the strength, pause before touching the floor and return to the starting position.  If not, catch your body with your hands and push back up to the starting position.  This is an eccentric exercise and will take a toll on your hamstrings, it should therefore be done no more than twice a week with recovery time between days.  

Try 6-10 reps 2-3 sets with 1-3 minutes rest between sets, stop if you experience cramping or if your form starts to break down.

Single Leg Squat

You should be able to perform a normal squat with good technique before attempting a single leg squat.  If you are new to the exercise, start standing tall with a chair behind you.  Straighten one leg out in front of you and lift it off of the ground a few inches, then with control, bend the knee of your supporting leg and hinge the hips backwards to lower down to the chair.  Once you touch, push through the heel and mid foot of the supporting side to return back up to standing.  You can have your arms out in front of you to help with balance.  You can use the chair as a means to progress, a higher seat will be easier, lower will be harder.  

You can progress to eccentrically lowering to the bottom of your range of motion, either with your leg out in front of you or with your foot/leg held by one or both of your hands.  Lower with control till you reach the bottom, then lower your leg and push back down with two.  You can work on this being sure to control the supporting leg, not to allow the knee to fall inward or outwards.  This will help you build up your strength until you reach the bottom of your range, push back through the heel on the supporting side to return back to a standing position.  

Try 6-10 reps, 2-3 sets, 1-2 min rest, stop if your form starts to fail

Hypers

Hypers or hyperextensions can be completed with a ball, on a bench or with a Roman chair.  Laying prone (face down) with your legs extended straight out behind you with your feet slightly turned out and your pelvis supported, your core and glutes engaged and your back long. You can cross your arms across your chest or place them behind your head.  With control slowly lower forward, hinging from the hips, you can keep the back straight to emphasize hamstrings or you can round your upper back and tuck your chin slightly to emphasize glute activation.  While activating your core come back into a straight line while keeping the pelvis and lower body stable.  Repeat until reps and sets are done, you can hug a weight to your chest with this exercise, however it is recommended that you only do this when working with a stable surface. 

Try 8-15 repetitions 2-3 sets with 1-2 minutes rest between, stop if your form begins to fail.

Hamstring Curl with Ball

Begin by laying on your back with your feet on a ball (this can be performed as a single leg or double leg exercise).  Contract your core and lift your hips up off of the floor so that the body is in a straight line from your feet to your shoulder.  Maintaining your body position.  Bend the knees and bring your ball toward your body with control.  Then slowly extend your legs until the knees are straight but not locked.  Keeping the feet wider apart will provide more stability than if they are closer together.  Try to keep your toes pointed upwards.  

Try 6-12 reps, 2-3 sets, 1-2 min rest, stop if your hamstrings begin to cramp or if your form starts to fail. 

Bridge with Ball

Begin by laying on your back with your heels on a ball, have your arms by your side (or at shoulder height if you want it to be harder) and your knees bent.  Pushing into your heels, brace your core and push your hips up off the ground until your shoulders and knees are in a line.  Pause at the top before lowering the pelvis back to the floor with control.  

Try 8-12 reps, 2-3 sets with 1-2 min rest between, stop if your hamstrings begin to cramp or if your form starts to fail.

Bear Crawls

Start on your hands and knees with your shoulders stacked on top of your wrists.  Pull your toes under and push your pelvis up into the air with your back straight.  Try to keep your shoulders relaxed while you look at the ground.  Move forward by stepping your right hand and right leg forward followed by your left hand and foot. Continue to ‘crawl’ forward on your hands and feet until you reach your desired distance.  Turn around and come back.  This is a good distance and timed exercise.  

Do not attempt this exercise if you have sustained a concussion or have any condition that is impacted by changes in blood pressure. 

PROPRIOCEPTIVE EXERCISES

Walk on Textured Surfaces

You can challenge your proprioception by walking on balance stones, or other textures.  You will automatically change your gait when you walk on these types of surfaces with bare feet, which will have an influence on your proprioception.

Balance Boards

Balance boards of all levels of difficulty are great for challenging your proprioception as well as your balance.  Different levels of difficulty will challenge the body's proprioception.  The more challenging the board the greater the adaptations.  Always be safe when using equipment and work within your current fitness level, injury will delay results.

Bodyblade

The Bodyblade is a great tool to incorporate proprioceptive challenges for the upper body. The motion of the blade creates perturbations which challenge the core, and the stabilizing muscles of the shoulder complex.  You can use the blade going forward and back, side to side or up and down, holding the blade with one or both hands.  It can also be used in conjunction with balance exercises and balance boards.  

Try 30 seconds on and 30 seconds, stop if your form starts to fail or you lose the rhythm.

References

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Ball, C. (2019, January 15). Neuromuscular training & Why it is important?. InSport Clinic NQ. Retrieved from https://sportsclinicnq.com.au/neuromuscular-training-why-it-is-important/

Clausen, B., Holsgaard-Larsen, A., & Roos, E. M. (2017). An 8-week neuromuscular program for patients with mild to moderate knee osteoarthritis: A case series drawn from a registered clinical trial.Journal of Athletic Training,52(6), 592-605.

Cook, G., Burton, L., & Fields, K. (1999). Reactive neuromuscular training for the anterior cruciate ligament-deficient knee: A case report.Journal of Athletic Training,34(2), 194-201.

Dargo, L., Robinson, K., & Games, K. E. (2017, November). Prevention of knee and anterior cruciate ligament injuries through the use of neuromuscular and proprioceptive training: An evidence-based review.Journal of Athletic Training,52(12), 1171-1172.

Hadzovic, M., Ilic, P., Lilic, A., & Stankovic, M. (2020, January). The effects of a knee joint injury prevention program on young female basketball players: A systematic review.Journal of Anthropology of Sport and Physical Education,4(1), 51-56.

Kristianslund, E., Faul, O., Bahr, R., Myklebust, G., & Krosshaug, T. (2012). Sidestep cutting technique and knee abduction loading: implications of ACL prevention exercises.British Journal of Sports Medicine,48, 779-783.

Krutsch, W., Lehmann, J., Jansen, P., Angele, P., Fellner, B., Achenbach, L., ... Loose, O. (2020, February). Prevention of severe knee injuries in men's elite football by implementing specific training modules.Knee Surgery, Sports Tramatology, Arthoscopy,25(2), 519-527.

Neuromuscular training: what is it and how does it work (2020, August 1). InTrueSport. Retrieved from https://truesport.org/preparation-recovery/neuromuscular-training/

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Saunders, N. W., Hanson, N. J., Koutakis, P., Chaudhari, A. M., & Devor, S. T. (2012, November). Figure skater level moderates balance training.International Journal of Sports Medicine,52.

10 Best speed ladder drills for soccer (2016, May 9). InFitnesshealth.co. Retrieved from https://fitnesshealth.co/blogs/speed-training/40956932-10-best-speed-ladder-drills-for-soccer