Examples of isokinetic exercises
Isokinetic exercise examples are not that common.
A true isokinetic exercise occurs when a muscle (or group of muscles) is activated (contracts) and the length of the muscle shortens at a constant velocity (speed). This is actually not that easy to replicate and generally requires specialist exercise machines that have the ability to rapidly change the amount of resistance opposing the movement in order for the muscle to reduce it length at same speed during a contraction.
Example of isokinetic exercise equipment
Although this equipment is often very expensive, some companies now manufacture what they refer to as isokinetic exercise machines, that do have the ability to rapidly alter the resistance output. While most of go some way toward being an isokinetic exercise, most are not true examples of isokinetic exercises. Cybex is probably the most well known example of a brand that specifically manufactures 'isokinetic exercise equipment' (among other types of equipment).
Benefits of isokinetic exercises
Isokinetic exercises have several benefits. For example, it is believed that the ability of the isokinetic exercise machines to vary their resistance levels, results in less change of injury (or re-injury in the case of rehabilitation). The force opposing the movement during concentric contractions should not be greater than the muscles can exert (minimising the risk of injury to that muscle). Another benefit is that isokinetic exercise equipment offers allows athletes to safely conduct resistance training throughout the required range of movement for the specific action they require (think baseball). This means that muscles fibres get worked through the entire range, not just at certain joint angles that may be the focus of isometric contractions or at the most mechanically disadvantageous angles in an isotonic contraction.
Do the benefits of isokinetic exercises outweigh the costs
I think isokinetic exercise equipment is great. I love the technology, I love the mechanical principles involved and the ingenuity. However, for the average member of the exercising public, the cost probably outweighs the benefits of isokinetic exercises in almost every example I can think of. There is a reason why most gyms do not stock isokinetic exercise equipment. However some isokinetic exercise examples, where I believe the benefits can outweigh the costs are listed below.
Isokinetic exercise examples - Exercise Bike
The main isokinetic exercise example for non-professional athletes are isokinetic exercise bikes. These can be useful for a wide range of people (from unfit beginner to professional athletes). Because of the cycle motion (as opposed to a free movement like a baseball pitch or swing), it is considerably easier (from a mechanical complexity point of view) to build a commercially viable isokinetic exercise bike. That being said, I must be honest, I use quite a standard exercise bike as I am not at high risk of injury (my legs are used to cycling!), and I am not a professional athlete (well... I'm still waiting for a call from the NFL or NBA... but I suspect that call might be a while coming...).
Cybex versus Nautilus
Cybex arc trainer versus high quality exercise bike
It doesn't take much of a comparison for most people to decide whether to get an isokinetic exercise bike or a good quality conventional exercise bike. Take for example the Cybex arc trainer. This type of bike is often promoted by retailers as an isokinetic exercise bike. Although, as we discussed earlier whether 'true isokinetic contractions' occur or not is a different story (and for which muscle groups involved in the cycle?). Nonetheless, there is no denying that the Cybex arc trainer is an excellent piece of machinery. However, at the time of writing the best price I can find for this equipment is through Amazon at $2995 (some places had it retailing for up in the high $4000's!).
Now the Nautilus U514 is a great quality conventional exercise bike (this is actually pretty similar to mine, just a newer model). So for this piece of machinery (also excellent in my opinion), you are likely to be set back about $400-$600 (RRP $599 but currently on Amazon for $365). You can see why I made this choice. Now if money wasn't an option, sure the Cybex arc trainer is probably better if you are purely after the benefits of isokinetic exercise. But for most of us.... the difference can be difficult to justify and the nautilus has a smooth magnetic eddy resistance system which should also minimize the chance of muscle injury; (+ it also has everything else you can think of... programs, heart rate monitor + interface with external heart rate monitors, reading rack, water bottle holder, fan, rear stabilizers, transport wheels, adjustable handlebars, fore / aft seat adjustment, oversized pedals, oversized saddles etc. etc.).
- Isometric contractions
Isometric contractions refer to a certain type of muscle contraction where the muscle spindles are activated but the overall length of the muscle remains the same. For this to happen, during an isometric contraction, no movement occurs at...
- Isotonic contractions
Isotonic contractions refer to a specific type of muscle contraction, where the tension on the muscle remains the same, however, the length of the muscle does not. Understanding isotonic contractions is important for anyone who wants to increase...
Testing versus training
Due to the expense and complexity of isokinetic exercise equipment, often they are used in specialist sports medicine rehabilitation facilities or amongst professional sporting teams. When the equipment is used for testing purposes, often the trainer or sports medicine doctor will be looking for peak force, power and particularly muscle imbalances (for example from one side to another). As an athlete trains you would expect to see improvements in peak force and power, while maintaining muscle balance as much as possible. Muscle imbalances are frequently identified as a root cause of injury amongst sports that have a single sided dominance. Some examples of sports where athletes may be at risk include baseball, golf, tennis and to a lesser extent jumping sports (athletics) and football (think soccer... not gridiron).
Examples of Isokinetic Exercise - Baseball
Here we see what most would call an isokinetic exercise, practicing a baseball 'chop' (strengthens useful exercise for hitting the ball out of the park). You can do a lot of other useful exercises with this type of Keiser equipment; just about anything you can think of with a conventional weight / pulley system is possible with this equipment. As with most expensive specialist pieces of isokinetic equipment it is used extensively for testing as much as training (there are a variety of data output to assist in fine tuning athletes or during a rehabilitation program).
Examples of Isokinetic Exercises - Knee extension
Here we see a conventional knee extension (and flexion) on a Biodex. Biodex exercise equipment (as with most true isokinetic exercises) tend to focus on predominantly on one joint. It is almost impossible to do a compound movement (involving two or more joints) and maintain a true isokinetic movement. It is usually possible to set biodex equipment to worth both in both directions (in this case knee flexion and extension).
Examples of Isokinetic Exercises - Ankle dorsi flexion and plantar flexion
Here we see a Biodex set up for the ankle. In this mode it looks like it is set to oppose both directions of movement (you can see his calves work hard on the plantar flexion and his tibialis anterior working hard on the dorsi flexion). You can also see the computer interface to the side where power output etc. will be reported.