Lack of Strength and Power
Many research articles that have been published in the last decade indicate that low impact exercise, strength and power training of the legs, stretching of the spine, hips, and lower extremities, and range of motion activities are the best means to limit stiffness, reduce joint pain and reduce fall risk.
A team of researchers performed balance testing, strength testing, and dynamic and functional testing of healthy adults. The results revealed noticeable weakness of the hip and thigh muscles occurring as early as 50 years in women and 60 years in men. The researchers encouraged all persons to do preemptive balance training, strength and functional activities to reduce the amount of weakness and thus potential for falls.
Basics of strength and power training
Current research shows that those who have sufficient strength and power in their legs and trunk are less likely to have falls and hurt themselves compared to those who do not. Strength and power are necessary to get up out of a chair, walk up or down steps, cross the street, or just answer the door safely.
There are three common questions that I answer frequently with our patients, family, and friends
- What is the difference between strength and power?
- Why are strength and power so important in fall prevention?
- What exercises can I do to improve my strength and power?
In this post I will answer these questions in reference to general health and well-being as well as fall prevention.
What is the difference between strength and power?
This is a good time to explain the difference between muscle strength and muscle power. Strength is defined as the maximal force that a muscle can produce against a given resistance, while power is defined as the product of force and speed.
When discussing strength in relation to one’s physical body, it often refers to how much weight a person can lift, move, carry, or pull a certain distance.
Strength
The formula for strength is:
- Force = mass x distance, or
- Force (strength) = mass (weight) x distance (how far you can move it), or
- Strength = weight (resistance) x distance
One example might be the act of standing from a chair without using your hands. Your body weight is the resistance and the distance is the number of inches measured from the height of your chair to your lateral hip bone when standing up straight. There are standard values established for varying age groups over age 50 years to compare with yourself or the person you are helping. Strength is the amount of muscle force a person has in order to accomplish a physical task.
The essential question here for many truly is, do you have sufficient muscle strength to get up off of the floor in case of a fall?
Power
The formula for power is:
- Force = mass x distance/time
Power has a time element. It refers to how fast a weight or object can be moved a certain distance. As mentioned above, transitioning from sitting to standing from a chair without using your hands can be a measure of strength in older persons.
So, how can we modify the exercises to measure power? Researchers have already figured it out for us. It is called a “30 second sit to stand test” developed for those persons over 60 years of age. The test is designed to count how many times a person can perform a sit to stand from a chair in 30 seconds, adding the time element in order to determine one’s power.
Again, researchers have established standards for various age groups with which a person can compare themselves. Before you get started on an exercise program, take the balance-killer quiz below to see how you may be at risk for falling.
Why are strength and power so important in fall prevention?
Studies show that strength and power training, alongside static and dynamic balance training, play a significant role in preventing falls and increasing bone mineral density to decrease the incidence of fractures from falls.
Additionally, having the strength and power to get one’s self up off of the ground due to a fall can minimize fear and the need to call 911 or wait for someone to discover that one has fallen. I had one patient relate to me that she lay on the ground for several hours because she did not have her phone with her, did not have an emergency alert device, and lived alone. Thankfully, a friend who had been trying to call her came by and discovered her on the floor but had to call 911 because she was too weak to get up off of the floor, even with her friend’s help.
Strong powerful muscles can give us the ability to adjust to trips, mis-steps, inadvertent bumps, as well as get up off of the floor, unless a serious injury has occurred.
Next Steps
The next step, or maybe even the first step, is to get going. For details on how you can implement a simple exercise program to increase your strength and power, please read my blog post “Training methods to develop strength and power.”
