Hyperextension of the knee joint occurs when the knee surpasses its natural and neutral anatomical position and extends to the point where it creates a posterior convexity in the legs. In simpler terms, the knee joint becomes hyperextended when it bends too far backward.
Hyperextension of the knee is a relatively common injury in both dancers and athletes; however, anyone can suffer this type of joint injury as the result of a false step or an accidental fall on concrete. When this type of hyperextension occurs, there is a genuine possibility of injury to one or more of the various tendons and ligaments. The ACL, or Anterior Cruciate Ligament, is especially susceptible to this type of injury and significant damage can be done even with a mild and momentary hyperextension.
Therefore, it is essential that we learn as much as we can about this common injury, including the leading causes, the most common symptoms, how it is diagnosed, and its relevant treatment.
WHY IS DO HYPER-EXTENDED KNEES BECOME A PROBLEM?
In human beings, the knee joint stands as the central joint of the lower limbs. It is formed by the union of the femur in the distal position and the tibia in the proximal position. The knee joint also contains a small bone known as the patella, which articulates with the anterior and inferior portion of the femur.
Now, while this isn’t an emergency problem for the knee such as needing urgent surgery after an Arthroscopy; it is still a significant problem.
The knee joint performs mostly flexion and extension movements, although it does allow for a small degree of lateral rotation. The joint receives crucial stability by a complex array of ligaments and powerful leg muscles. Therefore, the stability and strength of the knee joint depend, to a certain extent, on the ligaments that support it. Without sufficient muscle control and ligament support, the knee becomes unstable and ultimately vulnerable to injury.
PREVALENCE OF HYPEREXTENDED KNEES IN ADULTS
Several investigations have demonstrated that dancers and athletes, who typically possess higher-than-average joint flexibility, are more prone to injuries such as hyperextension of the knee joint. Furthermore, it is estimated that close to 40% of people ages 40 to 60 present inadequate flexibility limitation, which invariably leads to potential hyperextension of the joint. In fact, in a recent study, close to 90% of subjects with reduced flexibility limitation presented issues related to knee hyperextension.
WHAT CAUSES KNEE HYPEREXTENSION?
When excess weight or pressure forces the knee to extend beyond its normal range of motion, it typically causes soft tissue damage, including swelling and micro-tearing of the joint’s ligaments.
As such, known causes of knee hyperextension include:
- Pushing the femur or patella over the lip of the tibia and placing excessive stress on the ligaments inside the joint. This type of impact could be experienced after unexpectedly stopping by placing the entirety of the body’s weight on one leg while doing so.
- Traumatic impact against the front of the knee, which causes backward movement of the knee joint.
- Connective tissue disease.
- Misalignment of the bones of the joint.
- Muscular atrophy, especially of the quadriceps.
Since knee hyperextension can occur with different levels of severity, the symptoms experienced will likely vary from one patient to the next, depending on each person’s basal range of motion, the mechanisms involved in the hyperextension, as well as the patient’s muscular strength.
The most common symptoms of Hyperextension (Hypermobility) according to NHS England of the knee include:
Weakness of the joint: In cases of mild hyperextension, the affected knee becomes noticeably less stable than the non-affected one. The weakness of the knee joint can be described as a buckling sensation during movement.
Significant knee pain: After a hyperextension of the knee joint, localized pain in the knee is one of the most common symptoms. The location of the pain will depend entirely on the number of joint ligaments that have suffered damage.
Decreased mobility: Patients typically report having significant difficulty fully bending or straightening the leg after a hyperextension injury. Reduced mobility is likely due to swelling of the injured tissues that surround the joint. The most commonly affected internal structures include the anterior and posterior cruciate ligaments, the popliteal ligament and the meniscus.
Bruising and external swelling of the knee. Shortly after a hyperextension injury it is common to observe significant swelling and bruising around the affected joint. However, the exact onset of this symptom will depend on the severity of the damage. Typically, swelling will present before any noticeable bruising.
Knee effusion: With hyperextension injuries, it is possible that excess natural synovial fluid will leak from within the synovial bursa out into the joint itself.
DIAGNOSIS AND PREVENTION – HYPEREXTENSION KNEES
Diagnosis for hyperextension of the knee joint varies as much as the range of severity. For example, an individual who has suffered a traumatic and severe hyperextension of the knee may present heavy bruising, significantly reduced mobility, and great pain. On the other hand, an individual who has suffered only a mild hyperextension may present slight swelling and only slightly reduced mobility.
Therefore, most diagnostic processes will involve three factors:
Medical history of the patient: An individual with a history of previous knee injury is significantly more susceptible to a more severe hyperextension.
Physical exam: A thorough physical examination of the patient will help the doctor determine the severity of the injury. During the examination, the doctor will check the range of movement as well as the presence of swelling, bruising, and pain.
Imaging tests: When the severity of the injury is high, doctors will often request that one or more types of imaging scans be performed. This is especially so if the damage is severe enough to warrant surgical treatment.
HOW TO FIX MY HYPEREXTENDED KNEES?
Because inflammation is so prevalent during hyperextension, more often than not, the first step to fix a hyperextended knee should be to reduce any swelling. Patients are advised to apply ice as quickly as possible to help reduce inflammation. This will have the added benefit of numbing the joint and reducing pain and discomfort if any is present. Keep in mind that ice should never be placed directly on the skin because it can cause burns.
Depending on the severity of the injury, anti-inflammatory medication may be prescribed. Additionally, the use of compression bandages will be recommended to keep the knee joint and injured ligaments in a neutral position while they heal.
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In extreme cases, if there is significant tearing of the ligaments and other structures of the knee, surgical intervention may be necessary to mend the torn tissue.
In the majority of cases, keeping the leg elevated will provide the joint with extra support during the recovery process. In case the patient must move, it is often necessary to resort to crutches to prevent further injury. In some cases, the use of a wheelchair may be more prudent.
Total recovery from a hyperextension injury typically takes several months. Only very minor injuries can be expected to heal in less time. During this process, it is highly beneficial that the patient perform a variety of rehabilitation exercises to facilitate recovery and return the joint to a functional state.
In addition to the methods outlined above, patients may also resort to a variety of alternative methods. For example:
To help accelerate the healing time and reduce pain in a damaged knee joint, a paste made with turmeric can be applied directly to the skin. Turmeric is a potent anti-inflammatory herb that can help reduce swelling and discomfort in painful knee injuries.
There is also a wide variety of essential oils that can help patients recover from knee injuries quicker. For example, chamomile and lavender essential oils serve as potent analgesics and anti-inflammatory agents that can help reduce muscle spasms and swelling. Rosemary and peppermint essential oils have been suggested to improve blood circulation, which can significantly increase the rate of healing.
CONCLUSION – YOUR KNEES ARE PRECIOUS!
In many cases, hyperextension of the knee joint, as well as a large number of other ligament injuries, can be avoided by strengthening the primary and secondary muscles of the legs and hips.
It is also essential to increase the flexibility of the joint to boost stability during high-intensity movement.
Finally, always warm up before any sort of extended physical activity and allow a cooling down period afterward to ensure that your knee joint recuperates the necessary strength.
- Tegner, Y., & Lysholm, J. (1985). Rating systems in the evaluation of knee ligament injuries. Clinical orthopaedics and related research, (198), 43-49.
- Abbott, L. C., John, B., Saunders, M., Bost, F. C., & Anderson, C. E. (1944). Injuries to the ligaments of the knee joint. JBJS, 26(3), 503-521.
- Girgis, F. G., Marshall, J. L., & Monajem, A. R. S. A. (1975). The cruciate ligaments of the knee joint. Anatomical, functional and experimental analysis. Clinical orthopaedics and related research, (106), 216-231.
- Brantigan, O. C., & Voshell, A. F. (1941). The mechanics of the ligaments and menisci of the knee joint. JBJS, 23(1), 44-66.