Certified personal trainers are bound to encounter clients who either have had or need a total knee replacement. Here’s what you need to know.

Osteoarthritis (OA), the most common form of arthritis, a potentially devastating joint disease, affecting some 27 million adults per year and is on the rise. OA typically occurs in the hands, spine and hips affecting a multitude of joints particularly the knees.1 Obtaining a detailed history by the physician, via x-ray, where individuals will complain of symptoms of stiffness, low-grade inflammation and pain, makes the diagnosis.

According to the American Academy of Orthopedic Surgeons(AAOS), in 2003, there was more than 638,000 knee replacement surgeries were performed. (Source: National Center for Health Statistics; Centers for Disease Control and Prevention, 2003 National Hospital Discharge Survey). As the population of “baby boomers” continues to grow and ages, the number of people who will like undergo a total replacement will increase.4

The pathophysiology involves a combination of mechanical, cellular and biochemical changes. The interaction of these processes leads to changes in the composition and mechanical properties of the articular cartilage. Cartilage is comprised of water, collagen and proteoglycans, In healthy cartilage there is continual remodeling that occurs as chrondocytes(cartilaginous cells) that replace macromoelcules lost through degradation.

In Osteoarthritis, this process is disrupted leading to degenerative changes and abnormal repair response.2 The exact etiology is unknown. Risk factors include joint injury, obesity, mechanical stress, history of immobilization and trauma.


The most effective form of treatment of OA is education. Individuals should be thoroughly educated about the natural course of osteoarthritis beginning with the family physician and followed by the health professional(physical therapist) and personal trainer.

Medications commonly discussed with the patients by their physicians include; NSAIDS(non-steroidals) including ibuprofen, naproxen, cyclooxygenase inhibitors(celebrex) and vioxx. Steroid injections are another treatment option but are only able to be administered three times per year. Prolonged use of steroid injections can predispose an individual to osteoporosis.Total knee arthoplasty still remains a viable option for active patients suffering with loss of function, to manage the pain and disability associated with knee osteoarthritis.

The advancements that continue to develop are improved materials and surgical techniques providing the younger patient earlier return to functional activities and independence.5 Zeni et al conducted a study to examine what clinical factors will predict the decision to undergo surgery in individuals with end-stage knee OA. Functional data from one hundred twenty persons with end-stage OA was obtained. All individuals saw an orthopedic surgeon complaining of knee pain during activities. Functional evaluations consisting of measuring height, range of motion, functional ability to negotiate stairs were examined. Results: Forty-subjects underwent TKA within two years of the orthopedic evaluation. Persons who underwent the TKA were also significantly weaker in both the involved and uninvolved limb and had lower functional ability. Conclusion: The results of the study indicate that younger patients with full knee range of motion (ROM) who have a higher self-perception of function are less likely to undergo a TKA.3


Based on my 10 years of clinical experience and the research that has been published, those who develop osteoarthritis in the knee are because of several reasons. First, individuals continue to become obese which biomechanically places a greater load on the femur, tibia and patellofemoral joint. Haven treated and rehabilitated over 250 TKRs, I have noticed one common factor in all TKR patients: overdeveloped quadriceps that are very tight. According to the research and the work by Vladamir Janda, MD, the hamstrings are phasic muscles(weaker) and the quadriceps are postural muscles(tighter) and are stronger due to the research. Degeneration of the bone and cartilage is due to repeated mechanical stress overtime. Education on reducing repeated mechanical stress to the joint is something that is very easy to explain with simple suggestions.

Effective prevention techniques that you can teaching your client include:

  • To stretch their tight(postural) muscles(hip flexors, quadriceps and adductors). Strengthen weaker(phasic) muscles(hamstrings, glute maximus, medius and minimus)through exercises such as leg press, leg curl machine, side partial lunges with theratubing or holding a medicine ball.
  • Perform a minimum of 15-30 minutes 3x week of cardiovascular exercise(walking, biking, etc) followed with gentle stretching.
  • To cross train and utilize other exercise interventions such as water therapy classes, swimming, yoga and pilates to improve flexibility and core strength.
  • Seek a massage which can assist with improving flexibility while providing a relaxing feeling to stiff and tight worked muscles.
  • Motion is lotion. Teach you client to keep moving! Simple things as having your client get up and take breaks while at work and avoid prolonged sitting.


A longitudinal incision is made extending from the proximal to the patella to just distal to the tibial tuberosity. After flexing the knee to 90 degrees, the surgeon trims osteophytes from the femoral condyles, intercondylar notch and tibial plateaus. The surgeon uses a cutting guide to assist with preparation of alignment of the prosthesis. Anterior and posterior osteotomies(bone removal) are performed to the distal femur. Once the osteotomies are completed the final component is cemented in place and The incision is closed in layers with absorbable sutures and staples.4

Rehabilitation Management

(Source: Maxey)

The goal with physical therapy is to first restore mobility of the knee and reduction of swelling. Typically at 4 weeks post surgery, the individual has 90-100 degrees of flexion and by 8 weeks the goal is to have 120 degrees of knee flexion. This is important for climbing stairs, for transitional movements(getting in/out of car),etc. Physical therapy focuses on hamstring, glute maximus/medius strengthening to assist with daily activities such as sit to stand, climbing stairs, walking and standing that a individual daily performs. By 3 months post surgical, the individual has functional ROM and strength and by 6 months feels like they have a new knee!

Post Rehabilitation Training

Post therapy training should focus on continued aerobic activity(biking, swimming, walking), proper stretching of the tighter hip flexors, quadriceps and strengthening the weaker glute maximus, glute medius and hamstrings. Exercise such as; Leg press machine, bridging with ball, single leg bridge with ball, trunk rotation with cable/free motion, and diagonal partial lunges holding medicine ball are effective exercises. Designing an exercise program that avoids squatting and deep lunges. Biomechanically it places excessive compressive forces on the prosthesis and several orthopedic surgeons have also stated this as well. Continued balance training, dynamic core strengthening and human movement training is key to keeping the clients’ knees happy.


Osteoarthritis does not have to be a condition that renders someone complete incapacity. Also, surgery does not have to be the solution. However is a viable option for those suffering from chronic pain. We need to be more proactive with our clients and patients and educating them on proper diet, stretching and strengthening, cross training such as yoga, swimming, pilates and core strengthening can greatly improve their quality of life, reducing their likelihood of developing end stage OA of the knee while providing years of functionality and optimal health.


1. Lawrence RC, Delson DT, Helmck CG et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Arthritis Rheumatology. 58(1) pgs: 26-35. 2008.

2. Hinton et al. Osteoarthritis: Diagnosis and Therapeutic Considerations. Journal of American Family Physician. 65(5) Pgs: 841-849. 2002.

3. Zeni, Joseph A. et al. Clinical Predictors of elective total joint replacement in persons with end-stage knee osteoarthritis. BMC Musculoskeletal Disorders. Pgs: 1-11. May 6. 2010.

4. Maxey, Lisa., Magnuson, Jim. Rehabilitation for the Post Surgical Orthopedic Patient. Mosby. St. Louis. Pages: 270-280. 2001.

5. Starkey, Chad., Johnson, Glen. American Academy of Orthopedic Surgeons Athletic Training and Sports Medicine. 4th edition. Jones and Bartlett. Pages: 179-180. 2006.


Chris Gellert, PT, MPT, CSCS, CPT is the President of Pinnacle Training & Consulting Systems. Gellert offers educational workshops on human movement, home study courses on human movement, and consulting services. As a clinician, author, presenter, he has over 19 years experience having treated and worked with individuals of all ages with various spinal injuries, post surgical conditions, traumatic and sport specific injuries in industrial rehabilitation, outpatient and private practice settings. For more information, contact www.pinnacle-tcs.com or call 443-528-0527/(888)586-4188.



These resources are for the purpose of personal trainer growth and development through Continuing Education which advances the knowledge of fitness professionals. This article is written for NFPT Certified Personal Trainers to receive Continuing Education Credit (CEC). Please contact NFPT at 800.729.6378 or info@nfpt.com with questions or for more information.