As if divers didn’t have enough to
think about when entering the
water from a dive boat or dock,
here’s another problem: if you
don’t make a proper stride, you
can rupture your Achilles tendon,
which is a bad injury.
In a case reported by Jim
Marwood in the South Pacific
Journal of Underwater Medicine, as a diver stepped off with his left foot to
make a giant stride, he felt a blow on the back of his left ankle. He began
finning, but the ankle felt powerless. On return to shore, removing his
left drysuit boot was painful. He could walk with a limp, but extreme
pain prevented walking on soft sand. Although he had full, active ankle
movement, he was unable to rise on the left forefoot. He had ruptured
his Achilles tendon.
The diver was reasonably fit and had logged thirty-five giant stride
entries in the past year, loaded, as he was on this occasion, with coldwater
gear and heavy photographic equipment.
This time, however, a swell had caused the boat to roll. As he made
his stride, he was unbalanced by the boat’s motion, and the process of
shifting his weight removed support from his left heel. Because of his
forward thrust and the boat’s motion, his left ankle was carrying a load
of about 125 kg.
A direct blow may break the Achilles tendon, but about 60% of
injuries occur when amateur athletes are pushing off with a straight leg.
Obesity and sub-optimal fitness are predisposing factors. If you’re in the
process of taking a giant stride off of a small step and the boat rolls, your
risk of tearing the tendon is greater than if you had been stepping off a
broad dive platform. And if you’re heavily laden, entry from a sitting
position, while it might be less stylish, virtually eliminates the risk of
ankle injury.
To determine whether an Achilles tendon has been injured, a test
called the Thompson test requires the patient to lie prone with the knee
up at a right angle. When the calf is squeezed firmly, an intact Achilles
tendon will extend the ankle, while there will be no ankle movement if
the tendon is broken.
Rapid treatment of injuries to the Achilles tendon is essential for
optimum healing. A rupture requires surgical repair and weeks in a nonweightbearing,
below-knee cast. The diver described in this incident still
had difficulty supporting his weight on his left forefoot a year later.
— Ben Davison