Picture this. You’re in your car stopped at a red light at an intersection and you see an elderly lady crossing the street. As she’s slowly chugging along, you take a look at the pedestrian light and it’s starting to flash. She’s not even halfway across the street. Your heart starts racing and you think “Come on grandma, you can do it… it’s just a little bit farther. SUMMON YOUR STRENGTH!” The traffic light is about to turn green…
As we age, an aspect of walking that changes is gait speed. To walk, more than 1000 muscles need to be working properly to move 200 bones around 100 movable joints (Clark 1995). Age-associated decrease in gait speed is typically noticeable when a person hits their 60’s. Once you hit the 70’s, normal gait speed decreases about 12-16% per decade and 20% per decade for fast gait speed (Judge 1996). Normal walking speed is about 1.2-1.4m/s. Once walking speed slows to about 1.0 to 1.2 m/s geriatrics will tend to have trouble crossing the street safely before the traffic light changes (Langlois et al 1997).
Why do older people walk so slow??
There are several different reasons as to why there is a decrease in gait speed over time. Some of these factors are:
- Changes in how big your steps are (stride length),
- May walk slower to feel more stable
- Painful joints may hurt when walking so a slower walking speed limits the force absorption at those joints
- Decreased range of motion from degenerative changes such as osteophytes, etc. in the joints leading to changes in how you walk (motor pattern changes)
- Decrease in muscle strength due to loss of motor neurons, muscle fibers, and aerobic capacity (ability to use oxygen) leading to decreased mechanical power production
- Changes in the joint moments and powers so that there is an increase at the hip and decreases at the knee and ankle. [Peak ankle dorsiflexion displacement (moving ankle so toes point to the sky) during gait has been found to be a key discriminating factor between low-performing and high-performing groups of older people living independently.]
- During normal walking speed, the elderly consume significantly more oxygen (decreased aerobic capacity) for a given distance compared to the younger population, even though the elderly walk significantly slower (Waters et al.)
So what’s so important about Gait Speed anyways?
It turns out that walking speed has been shown to predict mortality, risk of falls, functional decline, and nursing home placement.
A decrease in gait speed of as little as 0.1 m/s will change a person’s ability to perform their activities of daily living by 10%. Geriatric people with a walking speed of less than 0.25 m/s are more likely to be dependent on others for 1 or more activities of daily living. A slowed walking speed may also increase the risk of falls, which can lead to a loss of independent living. Walking speed also has relationships with overall aerobic capacity so it can also be linked to heart health.
An increase in the normal walking speed over a 1-year period strongly predicts survival in the following 8 years. In this case, there is an almost 60% decrease in relative risk and almost 20% decrease in the absolute risk of death. This is a big deal as it has been found that this survival benefit still applies even after adjusting for other medical, functional, and psychosocial factors that are known to affect survival, and this effect is very consistent across many different subgroups of people.
What are some exercises to improve gait speed?
Lower extremity exercises can help to improve muscle force and flexibility, upright balance, and aerobic fitness. Things like yoga and flexibility training don’t help to increase walking speed, but can increase stride length and hip extension displacement to improve walking in general.
Here are some sample exercises you can try out! [Consult your family physician/chiropractor if you have an existing condition]
RANGE OF MOTION:
|Side Lying Leg Raises||1. Lie on your side with the top leg slightly behind the bottom one.2. Lift your top leg up to about 30 degrees keeping your toes pointed straight ahead.3. Return to start position and repeat. Switch legs.|
|Wall Slides||1. Stand with your buttocks and back against the wall.2. Bring feet to 1 foot from the wall, keeping your back against the wall.3. Lower down until your knees are bent to about 60 degrees.
4. Rise back up to starting position. Repeat.
These exercises need to be performed on a long-term basis. Changes won’t be noted right away, but over time you will notice increase in strength and flexibility. Visiting your chiropractor will help also to improve joint motion so you can perform these exercises and your activities optimally. A chiropractor can also give you advice on more exercises that you can perform that are customized for you and your goals.
Who knew that walking speed is so important? So teach these moves to your parents, grandparents, great-grandparents, and relatives. And if you see another elderly lady crossing the street slowly giving you anxiety, give her some tips so she can beat her street crossing time!