Hyperextension can cause severe damage to the muscles and tissues of your knees and legs, and also affects the mobility of the body. It can happen to anyone, but it is common in athletes that are associated with high-impact sports such as football, gymnastics, basketball, and soccer.
There are two types of hyperextension:
- Hyperextended Knee: It is a condition where the knee bends more than usual or straightens more than usual due to some injury.
- Genu Recurvatum Syndrom: It is a medical condition where the knee naturally rests a little straight rather than the usual bend.
This article provides you with the necessary information you need to understand, what is hyperextended knee, how it affects your body, how to identify the symptoms, and how to treat it. To understand the causes, symptoms, and treatment for the hyperextended knee, first, you need to understand the structure of the human knee.
In simple terms, the knee is what connects the thighs to the legs. We depend heavily on our knees to perform daily tasks, bending and kneeling, walking, and even doing high-impact tasks such as lifting heavy objects, playing sports, exercising, etc.
The knee is believed to be the most complex and vital synovial joint of the body because they hold the weight of your body. Also, the bones are not exactly perfect for each other, as the femur bone has a sphere-like end, while the tibia has a plate-like structure on the top. Thus, its structure is complex and aided by other components to make it strong.
Anatomically knees are joints, and their components are as stated below:
- Bones (femur, tibia, and patella, also known as kneecap): These are the most crucial part of the knees. These bones carry the weight of the whole body. The fibula is also a part of the knee, but it hardly does any movements.
- Ligaments (connects bones): Ligaments are fibrous connective tissues that connect the bones in a strong bond. They are responsible for controlling the movement of the knee from side to side and forward and backward motion. These ligaments are Collateral Ligament (LCL), Medial Collateral Ligament (MCL), Anterior Cruciate Ligament (ACL), and Posterior Cruciate Ligament (PCL). There is a special ligament called the meniscus, it ensures that the bones fit together and provide stability as the femur and tibia are two very different bones and do not interlock with each other as other joints do.
- Tendons (connects muscles and bones): Tendons are fibrous connective tissue, it attaches the muscles to bones. The quadriceps tendon connects the quadriceps muscles to the patella, and the patellar tendon connects the patella and tibia.
- Muscles: there are many muscles present in the knee that facilitate the bending of the knees and provide strength to the knees. Such muscles are the quadriceps and hamstring muscles.
- Nerves: Just like other body parts, there are nerves ending present on the outer side of the knee to provide sensory reception. It can help with the motor response as and when needed.
- Blood Capillaries: They have spread around and inside the knees to provide them with the blood it needs to function properly.
- Synovial Fluid: It is the fluid, that is present between the bone's connection point and around the ACL and PCL, which facilitates the movement of the bones.
If you want to learn more about the human joint knee, read this article by kenhub. Our concern is the movement of the joints, which is under the control of ligaments.
Ligaments are short bands of fibrous tissue which connect the bones. Apart from connecting bones, they have other functions such as controlling the movement of bones, providing strength to the joints, and spreading the weight exerted on the joint equally on the larger area.
The movement of the knee is controlled by four ligaments. The pair of ligaments that controls two types of motion as mentioned below:
Lateral Collateral Ligament (LCL) and Medial Collateral Ligament (MCL)
These ligaments control the side-to-side movement of the knees. These are present vertically on the sides of the bones. They make sure to provide support to the lateral and medial side of the knee, and also ensure that sidewise movement of the knee is regulated and not crossing a certain angle.
Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL)
These ligaments control the front-to-back movement of the knees. They are present horizontally between the femur and tibia in a criss-cross manner. They make sure that the knees do not bend more than usual. The forward bend of the knee is managed by ACL, while the backward bend is managed by PCL.
Usually, your knee aligns straight with your hip, but, it is not a perfectly straight line. The Q-angle is the angle formed between the quadriceps tendon (the fibrous connective tissue that connects the quadriceps muscles to the patella) and the patellar tendon (the fibrous connective tissue that connects the tibia and patella). Q-angle usually varies, but generally, this angle is 14 degrees in males and approximately 17 degrees. This angle may vary a little from person to person.
However, it is possible that because of many reasons, the knee starts to straighten or bend backward more than the Q-angle, which is a concern as it may cause severe damage to tissues and affect the daily tasks of the body. If the hyperextension is not identified in time or left untreated for a long, it can lead to the instability of the knee in long run.
Causes Of The Hyperextended Knee
Hyperextension can be mild or severe depending upon its cause of it. Some common causes are as mentioned below:
- High-impact blow to the knee due to sports or traumatic accidents
- When a ligament is sprained due to stretch, awkward landing, sport tackle, or even running
- When ligament tears or ruptures
- When the quadriceps muscles are weak
- When the hamstring muscles are weak
- Fractures in bones and structure surrounding the knee
The symptom of the hyperextended knee depends upon the cause and level of damage caused by the injury. Some of the symptoms are as follows:
- Moderate to severe pain in the affected knee: It is a most typical symptom as the area is affected. The degree of pain may vary for different causes and damage happened. Mild or moderate pain can be experienced when the knee is overstretched, or the ligament or tendon sprains. While moderate to excessive pain could be felt, if the damage is severe such as tearing of a ligament or tendon, fracture of a bone, etc.
- Swelling and bruising of the affected knee: These are general symptoms of bodily injury that cause hyperextension. The swelling and bruising may be more prominent in a short time if the damage is severe.
- Instability in the Knee Joints: As the bend is awkward, the knee feels unstable, and you may not feel strong in them and may experience a complete numbing session in the knees.
- Popping Sound: This popping sound usually indicates that the ligament has been ruptured.
- Weak Knees: You may face difficulty performing daily tasks such as walking or even standing without any support and it becomes progressively worsens if not treated in time.
- The structure of the affected knee is much different than the one that is not affected.
- Gait Pattern: Gait pattern refers to the style of walking. As the knee is bending or, the ligament has been torn, the pattern or the usual way you walk may change prominently.
Effects Of The Hyperextended Knee On The Body
- Posterior Lateral Corner (PLC) Injury: PLC is a combination of 3 components that can tear and lead to an unstable knee and disabled knee.
- Ligament Damage: Due to the impact of injury, the ligament can tear or rupture and causes weakening or instability of the knee. Timely treatment is required, or it can cause permanent damage.
- Meniscus Injury: A sudden blow or accident or any other sudden movement may affect the meniscus, it is a cartilage that works as the main balancing element of the knee for its smooth functioning. Damage to the meniscus can lead to a hyperextended knee.
- Difficulty in performing daily tasks such as walking, jogging, bending, and lifting heavy objects.
Treatment of the hyperextended knee depends upon the degree of hyperextention and damage that occurred.
Hyperextention may vary between mild and severe conditions depending upon the cause of hyperextension, the degree of damage that has happened to the knee, and the urgency of treatment (meaning the stage at which it has to be tended: early stage to the last stage)
For Mild Conditions
Hyperextention is categorized as mild if it is identified in the early stage and no severe damage has happened to the knee components. Causes of mild hyperextention could be weak muscles, unexpected bend of the knees in an angle that is not the average angle, and sprain or excessive stretch of the ligaments or muscles.
Mild conditions do not require any surgery, they can be treated by following options:
This procedure is the first method that doctors or physiotherapists prefer when dealing with a mild case of hyperextention. RICE stands for Rest, Ice, Compression, and Elevation. Let's learn what each of these means.
- Rest: As hyperextention causes damage to the knee, which is responsible for quite a lot of body movement. It is very logical, to restrain from putting more pressure on the injured knee as it may cause more damage and worsen the case. Thus, the person affected should give rest to the injured knee, meaning they should halt their activities that affect the knee. It can be different for different people, such as an athlete may have to consider rest for a few weeks from the games, and for any person, it could be not putting pressure on the injured knee while walking.
- Ice: Swelling is a common symptom of hyperextention. It can cause pain. To reduce swelling, one should apply ice (ice pack or ice inside a towel) to the affected area for 15 min for one ice treatment. Such ice treatment should be repeated throughout the day as per the advice of the expert.
- Compression: Compression refers to putting pressure on the affected knee with help of an elastic support band or a compression band. The preliminary function of compression is to reduce pain and provide support to the affected knee. It can be attained by wrapping a band around the knee in a specific way, by an expert, or wear a readymade compression band available in the market.
- Elevation: As in knee hyperextension, the knee can bend more than required. It is advised, that when laid down or in a sitting position, you should keep the knee elevated a little. For example, you can use a pillow to elevate your knee. As per the article on knee pain explained, “More recently, the extra category of "protect" was added so we now have the acronym PRICE.”, and “Protect: aims to prevent any further injury to the joint e.g. with a brace or crutches”
- Physical therapy and exercise: Often, the muscles connected to the knee become weak for any reason that can cause hyperextention. Thus, exercising can help you strengthen your muscles and improve your condition. You can exercise on your own with a doctor's approval or can sign up with a physical therapist for expert guidance.
- Medication: You can take some medication prescribed by an expert to reduce pain and swelling and speed up the recovery time.
For Severe Conditions
A severe case of hyperextension is when there is extreme damage to the knee and its supporting components. This damage could be a fracture in the bone, dislocation of the knee, ligament rupture, or tendon rupture. For these conditions, often surgeries are performed to repair and if needed, replace the affected area.
Depending upon the degree of damage and the affected area, surgery is performed. If the ligament or tendon is affected, it is possible that it can be repaired, and the hyperextention can be treated. If the ligament or tendons are beyond repair, then they can be replaced with ligaments and tendons of some healthy place in the body. A person may need to go through multiple surgeries if the first surgery was not successful or did not give the desired result.
Recovery from a hyperextended knee depends upon many factors such as the damage caused, the person's healing ability, and the procedure that is selected to treat the hyperextended knee. Usually, mild hyperextention takes up to 2 – 3 weeks of rest and treatment to get back to normal, while the severe cases where surgery is performed, it may take up to 6 months or more.
Surgeries are tricky, and there are chances that one may have to get operated on more than once to make sure that the knee is well treated. Once the surgery is successful, proper follow-ups and checks up are needed to ensure good recovery and no more damage happens.
You can use physical therapy to improve and recover faster.
Precautions one might consider to prevent facing such injuries:
- Exercise and eat food that strengthens your muscles, ligaments, and bones
- You should do a proper warm-up or stretch before you perform any high-impact task so that shock prevention may happen
- If you have suffered some form of a knee injury before it is advised that you wear braces or knee protection caps
It is important to understand that sometimes people can have slight hyperextended knees naturally which do not cause any discomfort. It is completely normal, however, it is advised to get yourself thoroughly examined by a medical expert just to make sure that you do not have any associated disorder that can cause hyperextended knees.
Frequently Asked Questions
Are Hyperextended Knee And Acl Tears The Same?
A hyperextended knee is a condition where the knee keeps bending backward which causes severe damage to the muscles, tendons, and ligaments around the knee. This can happen due to many reasons. ACL (Anterior Cruciate Ligament) is one of the 4 important ligaments of the knee that controls the mobility of the knee in certain directions and angles only. ACL tear is when the ligament breaks due to any reason, this can be one of the reasons a knee may hyperextend.
Thus, an ACL tear is one of the possible reasons for hyperextension of the knee.
What Is Genu Recurvatum Syndrome?
Genu Recurvaum syndrome is a condition in which the knee bends more than the normal or says neutral bending point naturally and not because of any injury. This can be the cause of naturally weak muscles, genes, nervous syndrome, or ligament laxity. Any person can be affected by this condition, however, a proper treatment such as medication, physical therapy, braces, or surgery can help you to deal with the condition and even cure it.
Can Babies Have Hyperextended Knees?
Anyone can have their knees hyperextended. It can be caused naturally or due to some injury. Thus anyone from a newborn to an elderly person can have hyperextended knees, however, it is most common in athletes that are indulged in high-impact and high-risk sports that are more prone to knee damage.
Are Women More Prone To Have Hyperextended Knees?
As per this research on joint laxity, the number of athletes affected with hyperextension is more in a woman compared to a man as a woman has a higher degree of knee laxity. Knee laxity affects the stability of the knee thus if for any reason the knee laxity is less it can lead to the tearing of the ligament which may cause hyperextension.
Is Hyperextension Good For Ballet?
Ballet is the dance of grace. There is a trend going on which says that hyperextension is aesthetically pleasing and desired by many ballerinas. However it is a double-edged sword, a slight mistake can cause you a lot of pain and damage. It is advised that you perform and train for this under a highly skilled expert if you want to have this condition to enhance your dance skill. You can read more about hyperextension for ballet in the article mentioned below:
- Ballet technique and hyperextension
- Hyperextension: the good, the bad, and the ugly
In this article, we learned about the condition of the knee which is known as hyperextension. In this condition, the knee bends in the backward direction more than the resting natural Q-angle (the angle between the upper and lower parts that our knee connects). This bending can happen due to a gene or any natural condition or any sudden injury that damages the knee components to some levels. Anyone can have a hyperextended knee but athletes are more prone to it.
This article focused on the hyperextention caused by external injuries that affect the movement of the legs. The movement of the legs is controlled by 4 ligaments namely the Lateral Collateral Ligament (LCL), Medial Collateral Ligament (MCL), Anterior Cruciate Ligament (ACL), and Posterior Cruciate Ligament (PCL). Damage to ACL and PCL can cause a severe case of hyperextension through injury.
These injuries can be caused by weak muscles, sudden landing, awkward jump, sport tackle, or an accident. Due to these injuries, the components of the knee can get sprained, stretched, or worse rupture which can cause hyperextension. You should exercise and strengthen the muscles to avoid such sudden shocks and also should take precautionary action to avoid injuries.
You can identify hyperextended knee by symptoms such as the unnatural bend of legs, weakness, and instability in knees, pain and swelling in the knees, popping sounds coming from the knees, and change in the pattern of walking (gait).
You should consult an expert to diagnose and treat the knees, this may be done using normal procedures such as the RICE method, physical therapy, and medication in case of mild hyperextension. But if the hyperextension is severe surgery is needed. Normally, the mild hyperextended knee can recover in 2 – 3 weeks but it might be 6 months for those who undergo surgery, note that recovery also depends upon your healing power and the damage that happened.
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- Cleveland Clinic: Hyperextended Knee (https://my.clevelandclinic.org/health/diseases/22481-hyperextended-knee#:~:text=What%20causes%20hyperextended%20knees%3F,can%20cause%20a%20hyperextended%20knee). Accessed on January 1, 2023
- International Journal of Aging Health and Movement Vol. 1 No. 1; January 2019: The Prevalence of Hyperextended Knee among Adults: A Cross-Sectional Survey. Accessed January 1, 2023
- American Orthopaedic Society for Sports Medicine; Biomechanical and Anatomical Assessment after Knee Hyperextension Injury. Accessed January 1, 2023