Common Knee Injuries: Transitioning from Pain to Functionally Fit

Knee pain comes in all shapes and sizes stemming from tendonitis, tendinopathies, patellofemoral pain, to the most common and functionally debilitating, osteoarthritis. The knee and hip complex The purpose of this article is to examine a few common knee injuries exploring their respective medical management.

Providing training strategies with each condition to help understand these conditions better, improving your clients’ return to or achieve optimal level of function.


Knee anatomyPatellar tendonitis is one of the most common knee injuries. In its “acute” condition, it is known to affect typically athletes or those individuals who perform repeated bouts of jumping loading the patellar tendon(basketball, and volleyball to name a few). However, physicians make the diagnosis on patient history, brief examination and observation.

A patient will complain of focal tenderness to the patella tendon/inferior patella. Aggravated by when the knee is extended(contracted), eccentric loading(walking down stairs) and repetitive activities such as jumping and running which load the tendon. However, a large body of research is refuting the cause of tendonitis. Where the actual cause is the mechanical discontinuity of collagen fibers, biochemical irritation that results from the damaged tendon tissue innervated by pain fibers.4

Traditionally, those suffering from patellar tendonitis have been advised to use NSAIDS, rest, and the use of an elastic patellar tendon strap to reduce to load to the patellar tendon, and/or reducing the load and training regime. If pain persists, clients are referred to see a physical therapist. If the pain isn’t completely resolved or treated properly, it can lead to patellar tendinopathy. Here the distinction with tendonitis can be traced to a single aspect: Time. The tendon thickens and biomechanically loads the inferior knee with increased pressure activating the pain receptors further.


Effective physical therapy management for either condition involves soft tissue manual therapy to reduce the load to the quadriceps, retinaculum(soft tissue around patella), taping technique, modalities as needed, stretching tight(phasic) hip flexors and adductors and strengthening glute maximus, medius/minimus and core strengthening.

Training Strategies

Effectively helping a client with patellar tendonitis/tendinopathy begins simply with education. This includes avoidance of squatting and eccentric exercises initially, since the moves involved can potentially reirritate the tendon.

Strengthening should be targeted to glute maximus via reverse lunges, diagonal reverse lunges targeting glute medius/minimus. According to the literature, these muscles are weaker biomechanically as lateral stabilizers. Core strengthening exercises such as trunk rotation with cable in a lunge position, hamstring curls with physioball and varying different angles of plank exercises are extremely effective.

Patellofemoral pain also known as (PFS), occurs frequently in young active adults, who typically presen with globalized diffuse knee pain that is described as “achy”. The pathogenesis of patellofemoral pain is unclear. Some authors has associated the development of PFS with malalignment of the patella within the femoral trochelar groove. This leads to increased stress on the patellofemoral joint.

Patellofemoral pain is associated with activities that increase typically with stair climbing, squatting, kneeling and running. Biomechanically, excessive pronation of the forefoot during gait, can lead to excessive or prolonged pronation of the foot and greater tibial and femoral internal rotation of the tibia and femur. These kinematic abnormalities lead to increased lateral patellofemoral joint stress to the patella. Other contributing factors such as muscle imbalances(quads>hamstrings), muscle inflexibility, amount/quality of running, type of shoe wear, and training regime are all variables that need to be assessed with this individual.

Medical Treatment:

Physical examination is typically brief by the physician examining ROM, palpating and brief tests to rule out other pathologies. Radiographs may be ordered which is per the discretion of the physician and individual’s presentation. Typically individuals are instructed by physicians to take NSAID’s for inflammation, modify activity level and pursue physical therapy.


Physiotherapy treatment consists of manual therapy that addresses muscle imbalances, stretching, taping to improve patellar-tracking and reducing pain. Restoring mobility prior to promoting stability is vital with these individuals. In a study by Crossley et al (2002), 71 subjects with patellofemoral pain for one month or longer were randomly allocated to a physical therapy group or placebo group. Treatment consisted of patella mobilizations, manual therapy, stretching, patella taping and home exercises. Where the placebo group received sham ultrasound and placebo taping.

Results: The physical therapy group demonstrated significantly greater reduction in pain and function.

Conclusion: Physical therapy can be effective in alleviating patellofemoral pain.5

Recommendations for Training:

Decrease load to quadriceps, stretching hip flexors, ITB, and hamstrings, balance strengthening of hamstrings vs. quadriceps, education on shoes, cross training via swimming and altering running surfaces(if client runs). The emphasis needs to be placed on strengthening the weaker(phasic) hip abductors — specifically, the glute medius and glute minimus.

Diagonal lunges using medicine balls or holding onto tubing are very effective, while reverse lunges will target glute maximus where modifications can be made to progress towards making the exercise more dynamic. This can be done with placing one foot standing on a half roll or unstable surface or using a free motion cable machine and performing the movement.

In a study by Prims & Van der Wurff (2007), who examined hip strength in females with patellofemoral pain and those without patellofemoral pain.

Results: Strong evidence was found for deficits in hip external rotation, abduction and hip extension strength.

Conclusion: Females with patellofemoral pain syndrome demonstrate a decrease in external rotation ROM, hip abduction and hip extension strength of the affected side as compared with healthy subjects.6

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 Those with OA will typically complain of stiffness, ache and varying levels of pain that are influenced with activity. The cause is thought to involved by capsule, muscle fatigue or bone involvement where excessive load overloads these structures and soft-tissue.

The pathohysiology 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 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 should always be discussed with their physician. NSAIDS(non-steroidals) can be effective to reduce swelling and inflammation.

Steroid injections are another treatment option, however are becoming more controversial because of the lack of evidence of long term relief and the high probability of negative changes on the bone, potentially leading to osteoporosis.


Physiotherapy has been shown to be effective to helping those individuals with OA knee pain.

Thomas et al (2009), conducted a literature review, where 15 articles pertaining to OA of the knee. The quality of articles reviewed were a high level of evidence(RCT Level II) which indicated that manual therapy can reduce knee pain and increase knee mobility. When combined with aqua therapy and stretching reduced knee pain and improved function.

Training Strategies

Because arthritis is a “process,” the most effective training is education and prevention. Training a client with knee OA should start slow with progressions made incrementally using a holistic approach. Cardiovascular training should be tailored and can be very effective. Starting with use of recumbent bike is a good starting point. This reduces the load to the hips and knee which can be progressed to the elliptical machine. This will also improve mobility, reducing blood pressure/heart rate, and aiding in weight loss. Stretching the tight(postural) hip flexors and quadriceps will reduce the load to the knee joint.

Yoga can also be an effective intervention which will improve flexibility, balance, strength and body awareness. Swimming or beginning with walking in the water also should be considered. This eliminates gravity and because of the buoyancy principle feels good and will strength the hip, knee and entire kinematic chain.

Strength training should focus on targeting the weaker phasic muscles such as the glute maximus, glute medius/minimus and hamstrings to reduce the load to the front aspect of the knee.

Stretching Exercises

Fig. 1. Hip flexor stretch Fig. 2. Hamstring stretch (keeping knee behind toe and not letting the trailing knee touch the ground)

Strengthening Exercises

Fig. 3. Hamstring curls with physioball Fig. 4. Trunk rotation w/diagonal lunge
Fig. 5. In place partial lunge with diagonal cable rotation


Whether a client has patellar tendonitis/tendinopathy, patellofemoral syndrome or osteoarthritis, understanding the pathology and limitations facing the client is the important first step prior to exercise prescription. Awareness is key. Any exercise prescription should be specific and personalized taking into account the age, severity of pain or history and the client’s goals. Train the client in single planes progressing to multi-planes targeting their “weak links” based on the science, can preventing future injuries from occurring and helping your client not only achieve their goals, but coming back for more!

About the Author

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, with extensive 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. He is presently pursuing an advanced Master’s Degree in Orthopedics/Manual Therapy in Australia. For more information, contact or email him at [email protected].


1. Lawrence RC, Delson DT & Helmck CG, 2008, ‘Estimates of the prevalence of arthritis and other rheumatic conditions in the United States,’ Arthritis Rheumatology, vol. 58, no. 1, pp. 26-35.

2. Hinton et al, 2002, ‘Osteoarthritis: Diagnosis and Therapeutic Considerations,’ Journal of American Family Physician, vol. 65, no. 5, pp. 841-849.

3. Thomas, A, et al 2009, Recommendations for the Treatment of Knee Osteoarthritis, Using Various Therapy Techniques Based on Categorization of Literature Review, ‘Journal of Geriatric Physical Therapy, vol. 32, no. 1, pp. 33-38.

4. Sanchis, V, 2010, Anterior Knee Pain and Patellar Instability, Springer, pp. 258-260.

5. Crossley, K, et al. 2002, Physical Therapy for Patellofemoral Pain: A Randomized Double Blinded, Placebo-Controlled Trial,’ American Journal of Sports Medicine, vol 30. no. 6, pp. 857-864.

6. Prins, M, & Van der Wurff, P, 2007, Females with Patellofemoral Pain Syndrome have weak hip muscles: a systematic review,’ Journal of Reearch, pp. 1-10.


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 [email protected] with questions or for more information.
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