Introduction

Cyclocentric exercise combines concentric and eccentric muscle strengthening during cycling. While concentric muscle strengthening occurs when the muscle being strengthened is moving to a shorter length, eccentric muscle strengthening happens when the muscle being strengthened is lengthening. An easy example of concentric and eccentric muscle strengthening is a bicep curl. When you curl the weight up, your biceps are shortening, so you are concentrically strengthening them. When you lower the weight back down, the biceps are lengthening, so you are eccentrically strengthening them.

By using a cycle ergometer, you are strengthening your lower-body muscles in these two different ways. The result is an increased focus on the main extensor muscles. These muscles include the quadriceps, which extend the lower leg; the gluteals, which extend the hip; and the plantarflexors, which assist in push-off during walking. Cyclocentric exercise is a safe way to help build strength and endurance in persons with and without disabilities.

How It Works

The cyclocentric ergometer incorporates a gliding seat system that can either be locked in place or allowed to move forward or backward. When the seat is fixed in its position, it serves as a conventional semi-recumbent bike. For cyclocentric exercise, the seat must be unlocked and allowed to glide within a range set by a therapist or the user. The direction of movement can be identified by the red arrows in the lower left picture:

Elastic cords, seen in the upper right picture, are attached to the base of the unit and determine the amount of resistance. They provide a pulling force toward the pedals. The more cords attached, the higher the force or resistance. This force can range from 10 to 100 lbs. As users pedal, they must resist against this force; otherwise, they are pulled closer to the pedals. If the individual can match this force, the seat position remains stable.

All brands of cyclocentric ergometers offer a range of different types of exercises with both the locked and cyclocentric features. Isokinetic speed control is excellent for building muscles, while the constant power effort is great for cardiovascular benefits. There are also many different programs that will allow the individual to do interval training or to simulate biking up a hill, as seen on the display screen on the right.

Help for Stroke Survivors

After a stroke, many individuals experience difficulty with ambulation, or walking. Some may not be able to ambulate independently, while others may be able to walk on their own but may have some difficulty keeping up their strength and endurance. There are many benefits of doing cyclocentric exercise at all stages of recovery after a stroke. Cyclocentric exercise may be used as a pre-ambulation re-training therapy or used in addition to an individual’s walking program.

Some of the many benefits include:

• Improved cardiovascular functioning.
• Improved balance and stability.
• Individuals’ weight bearing and limb loading are challenged.
• Assurance that equal work is done on both legs, without allowing for compensatory activity.
• Consecutive concentric and eccentric activation of the leg flexors and extensors.
• Enhanced proprioception (the knowledge of the position of the joint).
• Co-contraction of the muscles surrounding the knee which can decrease hyperextension of the knee while walking (a very common problem in stroke survivors).
• Enhanced kinematic pattern of walking before the individual actually ambulates.
• Improved ability to support oneself in stance phase during walking.
• Enhanced neurologic control.
• Increased ability to perform functional activities.
• Provision of a wider seat than most exercise bikes, which is a safety issue.

Research Results

Studies conducted with the hemiplegic population concluded that cyclocentric exercise is safe for both ambulatory and non-ambulatory patients. Over a 12-week period, patients were able to increase the resistance load with significant gains in functional ambulation activity.