Biomedical Engineering Reference
In-Depth Information
Forward axis
Vertical axis
Lateral axis
10
1
10
1
10
1
Ankle
Knee
Hip
Chest
Wrist
Elbow
Shoulder
Side/Head
Back/Head
10
0
10
0
10
0
10
-1
10
-1
10
-1
0.5
1
1.5
2
0.5
1
1.5
2
0.5
1
1.5
2
Speed (m/s)
Speed (m/s)
Speed (m/s)
Figure 2.5 Acceleration readings comparison from the walking (gray color lines) and running (black color lines)
test at each body location in
G
(1
G
5
9.8 m/s
2
). Walking test: 10 subjects, age: 29.4
6
5.8, height: 1.68
6
0.1 m,
weight: 62.9
6
12.8 kg. Running test: 10 subjects, age: 28.7
6
7.08, height: 1.68
6
0.1 m, weight: 63.2
6
12.4 kg.
The acceleration results for the different body locations are pre-
sented in
Figure 2.5
for the walking and running test for each individ-
ual axis. It is shown that high energetic locations (those that undergo
abrupt movements, such as the ankle and knee) exhibit larger accelera-
tions than other body locations. The larger accelerations were seen on
the knee (
B
1to
B
3
G
) and ankle (
B
2to
B
4.5
G
) locations for the for-
ward direction while walking. Acceleration variation for the same loca-
tions ranged from
B
1to
B
2.5
G
for the ankle and from
B
0.5 to
B
2.5
G
for the knee (walking test). Most other body locations had
accelerations while walking ranging from
1
G
.
These values are similar in magnitude at most locations of the vertical
and lateral axes (except ankle, knee, and the hip to some extent).
Lower body locations (ankle, knee, and hip) had a larger acceleration
component along the vertical axis. Acceleration for the average walk-
ing velocity of 1.4 m/s (
B
3.1 mph) was close to 0.5
G
for most of the
body locations (except the ankle and knee). Acceleration readings were
larger for running than for walking. Forward and vertical axes pre-
sented larger accelerations than the lateral axis. While running, lateral
axis accelerations (0.2
0.3
G
up to about 0.5
B
1.2
G
) exhibited little variation at all speeds.
The forward direction had acceleration readings from
B
4to7
G
for
