Weightlifting Knee Injuries and Pain

Knee injury in the gym
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The lower back, shoulder, and knee are the "big three" areas of injury for active people, including those who enjoy weightlifting. However, regular weight training can improve knee strength and prevent injury—as long as it's done safely and with good form.

Weight Lifting and Knee Injuries

It may seem like weight training would contribute to knee injuries. Lifts like deadlifts and squats do place high force on the knee joints, but these forces are applied mostly vertically and not horizontally or rotationally (twisting). The knees cope with vertical forces much better than horizontal and twisting forces, and with low-impact activities (such as weight training) better than high-impact ones.

While weight training is generally very safe for the knees, it's essential to practice proper form and follow the correct technique for each move. Even so, knee injuries do occur in weight training and in Olympic weightlifting. If you have an existing knee injury from another activity, inappropriate weight training exercises could make it worse.

In general, weight training is safe for the knees as long as you use proper form. The body is designed to manage vertical forces on the joints. However, sudden twisting movements, poor alignment, and pre-existing injuries may put you at risk for an injury.

Common Knee Injuries

For weight trainers and physically active adults, the knee joints endure a wide range of stresses and strains. In sports with twisting movements—such as football, basketball, hockey, and many others—ligaments that bind the complex bones of the knee joint together can be damaged, often severely.

Knee injuries, especially to the knee ligaments, are exceedingly common in sporting communities. These injuries can result in pain, swelling, and immobility that can be minor to severe. In knee ligament injuries, damage can range from a sprain or a slight tear to a complete tear in the most serious cases.

Anterior Cruciate Ligament (ACL) Injury

This ligament ties the femur bone of the thigh to the shin bone of the lower leg (tibia) and controls excessive rotation or extension of the knee joint. Anterior means at the front. A rear (posterior) ligament is also present. ACL injuries are seen mostly in athletes. Severe damage to the ACL usually means surgical reconstruction and up to 12 months rehabilitation.

In the gym, be careful not to allow twisting knee movements under excessive load, intentionally or accidentally.

Posterior Cruciate Ligament (PCL) Injury

The PCL connects the femur and tibia at different points to the ACL and controls any rearward motion of the tibia at the joint. The PCL is mostly injured with high-impact forces as a result of accidents and sometimes in sports activities where a sharp blow to the knee occurs.

Medial Collateral Ligament (MCL) Injury

This ligament keeps the knee from bending too far to the inside (medially). Damaged MCLs mostly occur from an impact to the outside of the knee, or even from an accidental bodyweight force when the leg reaches an unusual angle.

Lateral Collateral Ligament (LCL) Injury

This is the opposite ligament to the MCL. It's on the outside of the knee and controls excessive movement outward. This ligament connects the fibula (the smaller bone of the lower leg) to the femur. Similarly, the LCL is injured when a force pushes the knee outward.

Cartilage Injury

Cartilage prevents bones from rubbing together and cushions impacts. The two knee menisci are cartilages that cushion the inside and outside of the knee joint. Other types of cartilage protect the ends of the thigh and shin bones. When cartilage is torn or damaged, surgery may be necessary.

Tendonitis

Aggravated and overused tendons of the knee can cause disabling knee injuries. A related injury called "iliotibial band syndrome" (ITB) causes pain to the outside of the knee, often in runners, but it can occur in any overuse situation.

Rest, stretching, and two-week course of anti-inflammatory medication is often recommended. Using medication for longer than that can result in more side effects than benefits. For pain lasting longer than two weeks, consult a physical therapist.

Osteoarthritis

With age, normal wear and tear can result in osteoarthritis of the knee joints. In this condition, the cartilage that provides cushioning between bones deteriorates and causes bones to rub together resulting in pain and stiffness.

Prevent Weight Training Knee Injuries

There are steps you can take to minimize your risk of knee injury and pain while weightlifting. If you have an existing knee injury, follow the advice of your doctor or physical therapist.

  • Avoid certain exercises. Isolation exercises like the leg extension machine and leg curl exercises (either standing or on a bench) can stress the knee.
  • Deep squat with caution. If your knee is healthy, research shows the deep squat can protect against lower leg injury—when done with accurate technique, under expert supervision and with a gradually progressive training load.

Frequently Asked Questions

Can doing squats cause knee injuries?

If you are following proper squat form, squats should not cause knee injuries or pain. In fact, squats can be a great way to strengthen your knees. If you do experience pain while doing any squat variation, speak with your primary care doctor or a sports physician.

How do you prevent knee injuries?

Prevent knee injuries and pain by stretching your leg and knee muscles, following proper form when working out and weight training, and maintaining joint flexibility. Avoid sudden lateral movements and consider wearing knee supports to keep the muscle and joint secure.

What should you do if you hurt your knees while lifting weights?

If you feel sudden knee pain while lifting weights, stop immediately. Gauge the level of pain and discomfort you're feeling. If the pain is mild, follow the PRICE method to treat the injury by protecting, resting, icing, applying compression, and elevating your knee. If pain is moderate to severe, contact your physician.

When should you see a doctor for a knee injury?

Call your doctor if your knee pain is moderate or severe, if your knee is noticeably swollen or tender, and if you are unable to bear any weight on your leg.

A Word From Verywell

Weight training, when performed correctly, is generally safe for the knees. However, if you are concerned or have experienced a prior knee injury, you should talk to your doctor before beginning a new workout routine. Working with a personal trainer can be helpful in learning the proper technique and weightlifting form.

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5 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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