Knee Extensions

5.16.2015

Blog|Strength Training

The kneecap anatomically called the patella is the small bone embedded in a tendon in the front of the knee. The patellofemoral joint is where the kneecap and thigh bone meet. Below the kneecap there is a large tendon (patellar tendon), which attaches to the front of the tibia or shine bone. This mechanism allows the quadriceps, the large muscles of the front of the knee to extend the knee joint with a very slight rotation.

From a flexed position of around 135 degrees the knee extends or straightens to 0 degrees. Fluid-filled sacs called bursae serve as gliding surfaces for the tendons to reduce the force of friction as tendons move. Each meniscus, that is, the cartilage serves to evenly load the surface during weight-bearing, which also adds to the reduction of friction by disbursing joint fluid for joint lubrication. Having strong thigh muscles is important in reducing patellofemoral stresses during activity.

Until recently there has been disagreement in the literature as to which exercises and ranges of motion best accomplish the goal of low patellofemoral stress. It has been found that performing knee extension from 90° to 45° has significantly lower stress then isokinetic knee extensions and squatting movements. This is confirmed in the May 2014, Journal of Orthopaedic & Sports Physical Therapy. Therefore when prescribing exercise, non-weight-bearing quadriceps exercises are extremely important in managing joint stress especially in persons with knee pain.

Pendulum Leg Extension Starting from 90 degrees

Pendulum Leg Extension to 45 degrees

Training between 90° and 45° causes the least amount of patellofemoral stress and often allows pain free training enabling an athlete to re-strengthen the quadricep. Once knee pain dissipates and knee strength is normalized or increased the athlete can resume full range exercise.

Full range Pendulum Leg Extensions

6.2.2023

Closed And Open Chain

Open kinetic chain exercises of the lower limb are movements, where the distal segment is unloaded and free to move. The opposite is true of closed kinetic chain exercises, whereby there is enough resistance to prohibit free motion.

Closed kinetic chain exercises are movements such as squats, Pendulum Squat Pro, leg presses and lunges, while open chain exercises are actions like leg curls, leg extensions and the Pendulum Reverse Glute Ham.

The kinetic chain can be understood as interrelated joints and body parts working with one another during motion. This creates a chain of events that affects the movement of neighboring joints and segments.

The advantage of open chain movements is that they tend to be better at isolating muscle and often are selected for specific rehabilitation and used to accentuate performance. While closed chain movements in general would be classified as more functional and closely approximating movements that are used in sport and daily life.

Open Chain Reverse Glute Ham

Closed Chain Pendulum Power Squat Pro

Closed Chain Pendulum Power Squat Pro XT

5.11.2023

Arkansas Baseball Weight Room

5.11.2023

2-for-2 Method

Some trainers, coaches and athletes use what is called the 2-for-2 Method for increasing training load. The rule is if the trainee can perform two or more repetitions over one’s ‘repetition goal’ in the last set of an exercise, for two consecutive workouts, the weight is added for that particular exercise the next training session.