November 10, 2022 10 min read

Knee pain is a common and frequent problem with the overall prevalence of knee pain in Australia being approximately 19%. Though knee pain tends to worsen with age, any age group can experience knee pain, injury, or weakness. The situation can be acute, meaning that the pain came on suddenly, a short-term injury, or chronic, meaning it persists over a long period.

Water therapy and in particular water cycling can be an excellent exercise for those with dodgy knees because the water's buoyancy removes the burden of weight and impact on already painful joints, making it possible to use a joint with its full range of motion in water and build even strength in the support structures for the knee joint. The water's natural resistance also provides an excellent medium for strength training and cardiovascular workouts helping to reduce weight, a common problem with knee pain. Additionally, water's hydrostatic pressure encourages blood flow and supports unstable or healing joints.


Most of the time, knee pain or injury originates from overuse. The problem is that the knee joint can deteriorate further over time without being adequately addressed. It's better to catch knee pain in its tracks before too much damage is done, which is where water fitness comes in.

Joint pain in the knees can look a few different ways. The pain can radiate anywhere from the lower part of the thigh to the upper part of the shin. It can be deep and achy with a reduced range of motion, stiffness, tenderness, and swelling. There are also a few different causes and conditions associated with knee pain.

Like many aspects of health, "bad knees" are often hereditary. However, this doesn't mean you're doomed if you come from an extended family with knee problems. You can take plenty of measures to improve knee pain, prevent injury, and avoid any talks of knee replacement surgery down the line.

We need healthy knees to perform daily activities like walking, climbing stairs, and bending down. Taking care of them can prevent injuries and ensure long-term mobility.


Other symptoms associated with knee pain are:

  • Weakness or instability
  • Swelling, redness, or heat in the knee
  • Bruising around the knee
  • Your knee 'giving way'
  • Locking or clicking
  • Inability to straighten your knee
  • Stiffness



Anatomically, the knee joint comprises a group of muscles, ligaments, and cartilage. It is the largest weight-bearing joint in the body, so many impact injuries and impact-related wear and tear can affect this joint. It's a hinge-type synovial joint, which is meant for flexion and extension with only a little room for lateral or rotational movement.

Muscles: An essential knee joint musculature includes the muscles of the quadriceps (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius), the muscles of the hamstring (biceps femoris, semitendinosus, and semimembranosus).

Bones: The bones involved are the femur (thigh), patella (knee cap), and tibia (shin).

Ligaments: The four ligaments that connect bones to muscles are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), lateral collateral ligament (LCL), and medial collateral ligament (MCL).

Tendons: The quadricep tendon and patellar tendon are the tendons involved.

Cartilage: The knee joint features two menisci: the medial meniscus (inner side) and the lateral meniscus (outer side). These crescent-shaped pieces of cartilage act as the shock absorbers between the femur (thigh bone) and tibia (shin bone), distributing load and adding stability to the knee.

Synovial Fluid: This fluid is released to reduce friction between the knee joint structures. It is encapsulated and released by bursae.


Below is an overview of the most common causes of knee pain, but it is by no means an exhaustive list.


A common indication of achy knees is arthritis in the knee. Two main types of arthritis are osteoarthritis and rheumatoid arthritis (RA).

Osteoarthritis, commonly known as degenerative joint disease or wear and tear arthritis, is a painful arthritic condition in which the protective articular cartilage that cushions the ends of your bones wear down over time. As the cartilage deteriorates, bones may rub against each other, causing pain and discomfort. While osteoarthritis can affect any joint in the body, the knees are the most commonly affected.

Rheumatoid arthritis is an autoimmune disorder, meaning the body's immune system mistakenly attacks its own tissues. Unlike osteoarthritis, primarily a wear-and-tear condition, RA affects the lining of joints, leading to painful swelling that can eventually result in deformities of the joint and bone erosion. The knee is also one of the most commonly affected joints in rheumatoid arthritis.

Synovitis is a condition in which the synovial membrane is inflamed. This can be a side effect of rheumatoid arthritis or limited synovial fluid due to osteoarthritis.


The most common injuries at the knee joint are ligament injuries (ACL, MCL, LCL, or PCL) or cartilage injuries (meniscus). Knee ligament injuries make the joint unstable and cause wear and tear and arthritis later in life.

The anterior cruciate ligament (ACL) runs diagonally in the middle of the knee, providing rotational stability and preventing the tibia from sliding out in front of the femur. An ACL tear is one of the most well-known sports-related injuries, often resulting from a sudden stop, change in direction, or direct collision.

The medial collateral ligament (MCL) is located on the inner side of the knee joint. It resists the widening of the inside of the joint or prevents the knee from bending inward. Direct blows to the outside of the knee, commonly seen in contact sports, can lead to MCL injuries.

The lateral collateral ligament (LCL) is situated on the outer side of the knee; the LCL resists widening on the outside of the joint. It is less commonly injured than the MCL.

The posterior cruciate ligament (PCL) works alongside the ACL to maintain the tibia in place, preventing it from sliding backward under the femur. PCL injuries often result from direct impact to the front of the knee while it's bent, such as during a car accident or falling on a bent knee.

Meniscus tears can result from both traumatic incidents and degenerative processes. Athletes often tear their meniscus when twisting the knee, pivoting, decelerating, or due to direct contact. In older adults, degenerative meniscus tears can occur without significant trauma as the cartilage weakens and wears thin over time.


Bursitis refers to the inflammation of the bursa, a small fluid-filled sac that cushions between bones, tendons, joints, and muscles. When these bursae become inflamed, it can lead to pain and discomfort, particularly in joints that perform frequent and repetitive motion, like the knee.

Patellar Tendonitis

"Jumper's knee," also known as patellar tendinopathy or patellar tendonitis, is common in athletes who do a lot of high-impact running and jumping, like basketball and soccer players.


Inactivity is also often a culprit for joint pain. It lends itself to increasing joint stiffness and decreased ligament flexibility. Also, physical inactivity leads to weaker supporting muscles.


Physical activity, even if it is low-impact, is crucial for optimal health and healthy aging.

Water is beneficial for those with painful, weak, or unstable knees because it:


The most obvious benefit of water training is that it removes the necessity of bearing weight, which can be pretty painful for those with persistent knee pain or injury.


Water has an innate resistance that's about 12 times greater than air. This multidirectional resistance offers exercisers an opportunity to strengthen muscles from various angles. Strengthening the muscles around the knee joint can help stabilize it and reduce the risk of injuries.


The hydrostatic pressure exerted by water helps enhance blood circulation. Improved circulation can promote faster recovery and reduce inflammation, which is particularly beneficial for athletes with existing knee issues or those recovering from knee injuries.


The water's gentle embrace also helps to reduce pain for the exerciser so they can achieve a greater range of motion without intense pain. This helps to maintain and gain the flexibility needed for healthy joints.


When dealing with knee pain, one of the most common risk factors is carrying excess weight. For every three kilograms of weight, the weight placed on the knees is three times that.

In Australia, 2 in 3 adults (67%) are overweight or obese. That is a staggering percentage of people placing extra pressure on an already volatile knee joint.

A big step toward healthier knees is to lose any excess weight. This can be achieved most efficiently through combined cardio and resistance training. Both burn calories to offset calories consumed. Strength training helps build muscle, and with greater muscle gains comes higher metabolism. Meaning muscle burns more calories at rest compared to fat.

Of course, the added benefit is simultaneously burning calories and doing exercises that strengthen ligaments and knee structures as well as surrounding musculature to prevent further damage.


The unstable nature of water forces athletes to engage their core muscles and work on balance, which indirectly benefits knee health. Enhancing proprioception (the body's ability to perceive its position in space) can aid in better biomechanics and reduce the risk of awkward movements that might lead to injury.


Water fitness is the perfect cross-training solution for athletes who already perform many high-impact activities. It can keep athletes in shape without sacrificing joint health. Athletes who are accustomed to high-impact activities, such as running, basketball, or soccer, can experience repetitive stress on their knees. Water workouts can provide an effective training environment while minimizing this stress, preventing overuse injuries and preserving joint health.


Joining an aquatic group class can provide motivation and support. Being part of a group can boost morale, structure the exercise regimen, and allow individuals to share experiences and tips with fellow participants.


When someone suffers from chronic knee pain, arthritis, or even injury, knee replacement surgery is often recommended. However, if it is deemed necessary, there are ways that water therapy can help.


When someone is booked in for a knee replacement, this is an excellent time to focus on preparing for the surgery by starting the rehab process. It's designed to make the recovery from surgery faster and smoother.

A study that measured the benefits of knee prehab on post-operative success following a knee replacement found knee prehab to significantly improve outcome measures for up to 6 months post-op.

Prehabilitation begins typically 6-8 weeks before surgery, but there is no harm in starting sooner. The focus of prehabilitation is on strengthening the surrounding musculature of the knee. It will involve strengthening the quadriceps, hamstrings, and glutes while maintaining flexibility and range of motion.


Aquatic therapy is frequently associated with rehabilitation. While water fitness has numerous other benefits, it is associated with rehab for good reason. It is especially integral for rehabilitating lower-limb injuries that typically require non-weight-bearing activities, allowing them to start rehabilitating sooner.

The pool provides a safe and supportive place for those recovering to gain strength and confidence using their injured limb again. This study found that aquatic therapy improved knee strength in older women post-total knee replacement compared to land-based therapy. The added benefit of water is the hydrostatic pressure that encourages blood flow to injury sites and supports the joint to maintain stability.


In addition to serving as an excellent way for those with knee pain to get exercise, training in the water will help strengthen and stabilise the knee joint for pain management and prevention.

Water fitness and therapy with specialised equipment.


It involves pedalling stationary bikes submerged in water, merging the benefits of cycling with the therapeutic properties of aquatic exercise. Research has indicated aqua cycling is not just a trendy fitness routine but an evidence-backed way to help with knee pain. Specifically, studies have shown that this form of exercise is proven to be a beneficial exercise for knee osteoarthritis.

The bike provides proper alignment and control, so even those with injuries or muscle imbalances can rest assured they are getting a safe and effective workout. The water's resistance, combined with its buoyant nature, allows for low-impact, high-resistance training, ensuring that the knees are protected and strengthened simultaneously.


Underwater treadmills have emerged as a revolutionary tool in physical therapy and sports medicine, especially for knee pain patients. The buoyancy of water reduces impact on joints, making it an excellent medium for those looking to maintain or regain strength without exacerbating existing conditions.

For athletes, particularly, this modality can be indispensable. They may need at least one day of low-impact training but still want to engage in cardiovascular activities; the underwater treadmill provides that perfect balance. It offers relief from the typical stresses of land-based exercises and ensures that the heart rate is elevated and cardiovascular fitness is maintained.


Aquatic resistance bands are an innovative approach to strength training and muscle toning. Similar to using resistance bands on land, the aquatic environment provides the added benefit of water resistance. When these bands are used in water, they challenge the muscles even more, making every movement tougher and more effective.

One significant advantage of using aqua bands is their ability to target and strengthen the muscles surrounding the knee specifically. This enhances muscle tone and aids in injury prevention, making it a preferred choice for many looking to combine the therapeutic properties of water with strength training.

For people with knee pain or those recovering from a knee injury or surgery, the above exercises offer a level of safety that land-based activities do not. The risk of falling is essentially removed when exercising in water.


Dealing with knee pain doesn't mean an end to physical activity. On the contrary, it's a call to explore alternative methods that protect and heal. Water fitness and aquatic therapy are options if you or a loved one suffers from knee pain. With many physical and psychological benefits, water offers a comprehensive solution for those with dodgy knees.

Bear in mind that some knee pain can be manageable with water fitness and therapy, but if you think you have an injury or are yet to have a diagnosis for your knee pain, seek the guidance of a doctor or orthopaedic specialist.

Whether looking to rehabilitate after a knee injury or surgery, slow the impact on your arthritic knees, or search for a way to get fit without further aggravating your knees, water cycling is worth a try.

Also in Blog

Breast Cancer and Aquatic Exercise
Breast Cancer and Aquatic Exercise

October 20, 2023 10 min read

Aquatic therapy can improve strength, cardio, flexibility, balance, lymphoedema, chemo-induced neuropathy, as well as the anxiety & self-image affected by breast cancer.
Water Cycling for Anxiety & Depression
Water Cycling for Anxiety & Depression

September 04, 2023 8 min read

For those with anxiety and depression, the water's gentle embrace offers solace, strength, and a path to rejuvenation and wellbeing. 
Water Exercise for Bone Health
Water Exercise for Bone Health

August 31, 2023 4 min read

Water exercise is proving effective for bone health, has lower risks of fracture, & puts less stress on the joints. It also comes with less risk & additional health benefits. 
Get Started
Enquire today to get started