Page 104 - Journal of Special Operations Medicine - Fall 2014

ground impact forces. Higher winds can also increase PAB modified for desert boot.
parachute oscillations, adding additional ground impact
forces and resulting in a less-controlled landing. Winds
can also push a parachutist away from preplanned drop
zones into obstacles, power lines, rougher terrain, wa-
ter bodies, or trees. Tree landings are especially hazard-
ous because a collision with a tree can be followed by
an uncontrolled ground impact if the parachutist falls
from the tree. High winds can also drag soldiers on the
ground after they land and before they have time to col-
lapse their parachute canopies. Night jumps increase
injury risk because of reduced ability to see the ground,
to perceive distance and depth, and to appreciate the di-
rection of horizontal drift. These factors can lead to less-
controlled landings and reduced ability to see obstacles Original PAB.
on the drop zone. Combat loads increase descent veloc-
ity and may result in greater impact energy on ground
contact. At higher temperatures, the air is less dense,
resulting in faster descent velocities and higher ground
impact forces. 9

It will not surprise airborne soldiers that higher fitness
is associated with lower injury risk. It has been dem-
onstrated that soldiers who have greater upper body
muscular endurance (can do more push-ups) or greater
aerobic fitness (have a faster 2-mile run time) are at
lower injury risk. While great upper muscular endurance
may be related to the ability to pull on the parachute
risers and control the direction of lateral drift, possible bracing the ankle may result in injuries higher up the
reasons for the association between injuries and aerobic body, at the knee or hips, but this has been shown not
10
fitness are not clear. Heavier soldiers are at increased to be the case. Parachutists may want to consider the
risk, likely because they impact the ground with greater PAB, especially if they have had ankle problems in the
force. Older parachutists (older than 30 years) are at past. The PAB is described in the manual on static line
higher risk than younger ones. 6 parachuting (FM 3-21.220, Static Line Parachuting
Techniques and Training, September 2003).

Summary
Airborne personnel can take advantage of several fac-
tors to prevent injuries during parachuting. First, as a
result of technological and technique developments
and since World War II, the risk of injury is relatively
small (6 per 1,000 jumps). Understanding and acting
on known risk factors can reduce one’s risk even more.
Army doctrine is that jumps should not be conducted at
wind speeds above 13 knots, for good reason. Nonethe-
(above) New RA-1 parachute. less, any winds above 5 knots will increase injury risk to
(right) MC-6 parachute.
some extent. Although training should be conducted un-
der realistic conditions (night jumps with combat loads),
these should be the minimum necessary for tactical and
Parachute Ankle Brace
operational proficiency. Also, wearing a PAB will reduce
Among the most common injuries experienced by ankle injuries and should be considered by all parachut-
parachutists are ankle sprains and ankle fractures. An ists, especially those with prior ankle problems. A high
outside-the-boot parachute ankle brace (PAB) has been level of upper body muscular endurance and aerobic fit-
developed and shown to reduce the incidence of ankle ness is not only beneficial for general health; it also ap-
injuries by half. One common misconception is that pears to reduce the risk of injury in airborne operations.

96 Journal of Special Operations Medicine Volume 14, Edition 3/Fall 2014