Friday, May 17, 2013
Injury prevention technology at the combine
By Brad Stenger
Jesse Wright, strength coach for the 76ers, recently got himself a technology budget, something he'd never had before with the Sixers, a gift from his new GM Sam Hinkie.
He's stressed about it though.
"You've got a blank slate!" I said to him, failing to reassure.
"I can't get everything," he told me, "but I need to get the right things."
What are the right things for an NBA team that wants healthy, fit players and is willing to spend on technology?
Wright and I were taking in the NBA vendors show, an unpublicized sideshow at the draft combine, held each year in a Chicago hotel ballroom.
What are the disruptive digital technologies that offer a clear injury prevention payoff? Some candidates:
Next generation compression
The NormaTec system is the pair of black sleeves you sometimes see athletes wearing over their legs when television cameras look into the locker room before games. They compress the large muscles in the legs to improve blood flow and speed recovery.
The systems have been around since 2007 and are an established, widely used technology to help athletes speed recovery. Every single player on the Miami Heat has a $5,000 deluxe-version NormaTec Pro of their own. LeBron James owns three, including a custom, personally-fitted hips and legs version.
Custom fits aren't normally required. The sleeves are made from thick industrial nylon and zip closed around the leg. Air fills the sleeve; the tightness is controlled by embedded pressure sensors.
One leg of a NormaTec sleeve is split into five section compartments, overlapping zones that fill with air from the control box. The bottom compartment fills first, and on up the leg. The pressure builds and the compression benefit kicks in. When the sleeve is fully pressurized air flows into and through the sleeves in computer-controlled pulses that further stimulate recovery.
Evidence for NormaTec's effectiveness is more anecdotal than empirical. Gilad Jacobs, the CEO of the Newton, Massachusetts, company says that's not because the systems haven't been tested. They have been, by the likes of the U.S. Olympic Committee which took dozens of NormaTecs to the London Olympics -- but the U.S.O.C. is not publishing what they have learned in sports science journals, according to Jacobs.
Identifying fatigue that can lead to injury
The core of the Catapult system is a wearable sensor package that tracks and radios precise body position data on a working athlete to a base computer. The system gets its precision from the many sensors in the package:
- a GPS sensor (that works far better outdoors than indoors)
- an accelerometer that measures the force associated with an athlete's movement
- a gyro sensor that measures rotational displacement and a magnetometer
- a compass, that measures directional vectors and validates rotational movements.
The package, a little larger than an apple core, weighs a few ounces and hides in the pocket of a snug-fitting under-jersey.
Data from the Catapult system relevant to injuries comes in two forms. Over time, once a baseline value has been established, the data can indicate when a player is fatigued and show patterns which differentiate between fatigue associated with improving fitness and fatigue associated with overuse. Athletes recovering from injury can see clearly if they apply equivalent and balanced forces when playing, running, jumping and cutting, or if they are favoring the non-injured shoulder/arm/hip/leg/foot.
Catapult was developed by sports scientists at the Australian Institute of Sport and has been used widely for the last six years by Australian Rules Football teams. (Catapult U.S. headquarters are in Atlanta.) League-wide the teams share data and study the results, according Catapult's Gary McCoy, leading to not just significantly fewer injuries but also more plays per game.
The system tells coaches how far and how fast athletes have moved throughout a practice. (Universally as far as I can tell, leagues disallow the systems during games.) The system also distills a player's work to a single number that reflects cumulative effort -- PlayerLoad. PlayerLoad is compatible with other measures of athlete effort that come from heart-rate monitors, from SportVu game-tracking or from simply asking players how they're feeling at a given time. It all goes into the big database that Catapult enables. "We create a dashboard for coaches to see their athletes and how they're working," said McCoy.
It's a versatile tool that teams look to for changing culture. McCoy also told me how one unidentified NBA team that uses Catapult (Celtics, Mavericks, Rockets, Knicks, Spurs are customers listed on the company website) decided to post PlayerLoad numbers on the wall after practice. The team was concerned about the loafing going on during practice and felt well-informed peer pressure could help.
Jumping to test fatigue
Force plate technology wasn't on display at the vendor show but it was presented by Phil Wagner from Palo Alto-based Sparta Performance Science at the Midwest Sports Performance Conference held at the University of Kansas last weekend. Kansas has the force plates installed and uses the Sparta software to monitor athletes.
Sparta is also known for training Jeremy Lin prior to his rise to fame with the Knicks.
Wagner has athletes do a vertical jump on the force plate which produces a three phase “movement signature.” The pre-jump “load” phase, the key transition “explode” phase and the energy-sustaining “drive” phase appear as peaks and dips in the resulting data graph. Sparta delivers the data graphs from jump tests to Kansas players and coaches through a private Web interface.
Evidence suggests these movement signatures can be injury predictive. Given all of the running and jumping basketball players do, when ground force production (what's measured in the jump test) is inefficient the joints and tendons at the root of those inefficiencies pay a price and break down.
When measured at regular intervals during the season the jump test will also show fatigue. Players who say they feel 100 percent but produce significantly less force than they do at their peak clearly lack explosiveness, a surefire indicator that fatigue has set in.
Peak Performance Project (P3), a sports training company in Santa Barbara, has a similar technology, but uses right- and left-lateral jumps to measure force production. P3 has had an ongoing affiliation with the Utah Jazz since 2007. Both P3 and Sparta Science are currently talking to other NBA teams interested in adopting their systems.
Brad Stenger is a New York City-based journalist and researcher.