Study: Single-Sport Athletes Injured More
November 3, 2016
A study conducted by the University of Wisconsin School of Medicine and Public Health and funded by the National Federation of State High School Associations (NFHS) Foundation revealed that high school athletes who specialize in a single sport sustain lower-extremity injuries at significantly higher rates than athletes who do not specialize in one sport.
The study was conducted throughout the 2015-16 school year at 29 high schools in Wisconsin involving more than 1,500 student-athletes equally divided between male and female participants. The schools involved in the study represented a mixture of rural (14), suburban (12) and urban (3) areas, and enrollments were equally diverse with 10 small schools (less than 500 students), 10 medium schools (501-1,000 students) and nine large schools (more than 1,000 students).
Athletes who specialized in one sport were twice as likely to report previously sustaining a lower-extremity injury while participating in sports (46%) than athletes who did not specialize (24%). In addition, specialized athletes sustained 60 percent more new lower-extremity injuries during the study than athletes who did not specialize. Lower-extremity injuries were defined as any acute, gradual, recurrent or repetitive-use injury to the lower musculoskeletal system.
“While we have long believed that sport specialization by high school athletes leads to an increased risk of overuse injury, this study confirms those beliefs about the potential risks of sport specialization,” said Bob Gardner, NFHS executive director. “Coaches, parents and student-athletes need to be aware of the injury risks involved with an overemphasis in a single sport.”
Among those who reported previously sustaining a lower-extremity injury, the areas of the body injured most often were the ankle (43%) and knee (23%). The most common types of previous injuries were ligament sprains (51%) and muscle/tendon strains (20%).
New injuries during the year-long study occurred most often to the ankle (34%), knee (25%) and upper leg (13%), with the most common injuries being ligament sprains (41%), muscle/tendon strains (25%) and tendonitis (20%).
In addition, specialized athletes were twice as likely to sustain a gradual onset/repetitive-use injury than athletes who did not specialize, and those who specialized were more likely to sustain an injury even when controlling for gender, grade, previous injury status and sport.
Thirty-four (34) percent of the student-athletes involved in the Wisconsin study specialized in one sport, with females (41%) more likely to specialize than males (28%). Soccer had the highest level of specialization for both males (45%) and females (49%). After soccer, the rate of specialization for females was highest for softball (45%), volleyball (43%) and basketball (37%). The top specialization sports for males after soccer were basketball (37%), tennis (33%) and wrestling (29%).
The study, which was directed by Timothy McGuine, Ph.D., ATC, of the University of Wisconsin, also documented the effects of concurrent sport participation (participating in an interscholastic sport while simultaneously participating in an out-of-school club sport), which indicated further risk of athletes sustaining lower-extremity injuries.
Almost 50 percent of the student-athletes involved in the survey indicated they participated on a club team outside the school setting, and 15 percent of those individuals did so while simultaneously competing in a different sport within the school. Seventeen (17) percent of the student-athletes indicated that they took part in 60 or more primary sport competitions (school and club) in a single year. Among those student-athletes in this group who sustained new lower-extremity injuries during the year, 27 percent were athletes who specialized in one sport.
The student-athletes involved in the study were deemed “specialized” if they answered “yes” to at least four of the following six questions: 1) Do you train more than 75 percent of the time in your primary sport?; 2) Do you train to improve skill and miss time with friends as a result?; 3) Have you quit another sport to focus on one sport?; 4) Do you consider your primary sport more important than your other sports?; 5) Do you regularly travel out of state for your primary sport?; 6) Do you train more than eight months a year in your primary sport?
Although some sports (field hockey, lacrosse) are not offered in Wisconsin and were not included in the study, the study concluded that since specialization increased the risk of lower-extremity injuries in sports involved in the survey it would also likely increase the risk of injuries in sports that were not a part of the study.
Leland's Glass Childress Selected as 11th Michigan Inductee Into NFHS Hall of Fame
By
Geoff Kimmerly
MHSAA.com senior editor
March 9, 2026
More than two decades have passed since Alisha Glass took her final swing at a volleyball in a Leland High School uniform, and yet her accomplishments for her small-town school in Northern Michigan remain among the most notable in that sport’s history not just statewide, but at the national level.
Glass, now Alisha Glass Childress – who went on to star on three Penn State national championship teams and help the U.S. national team to a bronze medal at the 2016 Olympics – will have her record-setting high school career enshrined this summer as one of 12 honorees announced today as this year’s inductees into the National High School Hall of Fame by the National Federation of State High School Associations (NFHS).
Childress will be inducted as part of the 43rd Hall of Fame class at a ceremony during the NFHS summer meeting June 29 in Salt Lake City. The rest of the class is made up of four more athletes, three coaches, two game officials, one former state association administrator and one former fine arts educator. Childress was nominated by the Michigan High School Athletic Association.
She will become the Hall of Fame’s 11th inductee from Michigan, joining the MHSAA’s first full-time Executive Director Charles E. Forsythe (inducted 1983), River Rouge boys basketball coach Lofton Greene (1986), Warren Regina athletic director, softball and basketball coach Diane Laffey (2000), Fennville basketball and baseball standout Richie Jordan (2001), Grosse Pointe Woods University Liggett boys and girls tennis coach Bob Wood (2005), Bloomfield Hills Cranbrook hockey standout Jim Johnson (2007), Owosso football, basketball and baseball all-stater Brad Van Pelt (2011); Vermontville Maple Valley baseball national record holder Ken Beardslee (2016), retired MHSAA Executive Director John E. “Jack” Roberts (2022) and Dearborn Heights Robichaud football, basketball and track & field star Tyrone Wheatley (2024).
“My high school career at Leland, surrounded by such an amazing support system and community, was the essential first chapter of my story. It cultivated the grit and the fundamental love for the game that allowed me to reach the highest levels of athletics,” Childress said. “I’m proud of every medal and trophy, but I’m just as proud of the roots I planted back in high school that made them all possible.”
Childress graduated from Leland in 2006 with national high school career records of 3,584 kills, 680 blocks and 937 aces, and 296 aces for one season as a junior. Her aces records still stand, her career kills record stood until broken in 2024 by Shelby’s Navea Gauthier, and she remains third on the career blocks list. Glass continues to hold MHSAA records for single-season and career aces and also for her 48 kills in Leland’s 2005-06 Class D Final win over Battle Creek St. Philip. Childress also led Leland to a Class D runner-up finish in 2004-05 and the Semifinals in 2003-04. (All three tournament runs took place while girls volleyball was still played during the winter season before moving to the fall to begin the 2007-08 school year).
Childress earned the Miss Volleyball Award and Gatorade Player of the Year Award for Michigan as a senior, and her name is listed 19 times throughout the MHSAA girls volleyball record book. She also made Michigan's Class D all-state first team on the basketball court as both a junior and senior, averaging 18 points and 11 rebounds per game as a junior and 16 points, 10 rebounds and 3.7 blocked shots per game as a senior while leading her basketball team to Class D Quarterfinals both of those seasons.
“As our staff researched our first 50 years of female sports for our ‘Title IX at 50’ celebration during the 2021-22 school year, they told stories of several standouts who went on to collegiate, Olympic and professional stardom – and Alisha Glass stands out even among the greats,” MHSAA Executive Director Mark Uyl said. “Taking into account everything she accomplished individually and with her teams, and not just in volleyball but basketball as well, it’s a strong argument that Alisha Glass continues to set the bar as not only our state’s best female athlete all-time, but arguably the most accomplished volleyball player in national high school history. We are thrilled that she will be inducted into the National High School Hall of Fame.”
Also during high school, Childress played on the 2004 and 2005 USA youth national volleyball teams and helped the 2004 team to the North, Central America and Caribbean Volleyball Confederation (NORECA) championship, and was named Best Server at that event. After high school, she started all four seasons at national power Penn State and set the Nittany Lions to three straight NCAA championships, being named to the American Volleyball Coaches Association (AVCA) All-America first team twice and second team once.
Childress continued her career professionally and internationally, playing professionally in the United States and Puerto Rico, Italy, Turkey, Poland and Brazil and being named USA Volleyball Indoor Female Athlete of the Year for both 2013 and 2014. She led the U.S. national team to bronze at 2016 Olympics and was named Best Setter of the tournament, after being selected as an alternate for the 2012 Olympic team.
Most recently, Childress played for the Pro Volleyball Federation's Vegas Thrill in 2024 and 2025 and played in the league's first All-Star Match last season. She’s currently the head coach of the San Diego Mojo of Major League Volleyball and last summer also completed her first season as a coach with Athletes Unlimited. She previously served as an assistant coach with the Stanford University women’s volleyball program from 2019-21 – including during the team’s run to the Division I national title in 2019 – and also served as an assistant for the gold medal-winning U.S. national team during the 2018 Pan American Cup.
Childress is the daughter of Laurie Glass, who retired from coaching Leland after the 2023 season and ranks seventh in MHSAA girls volleyball coaching history for victories with a career record of 1,259-410-124. Glass led Leland to three Class D championships and five runner-up finishes. Childress’ grandfather Larry Glass ranks on the MHSAA girls basketball coaching victory list with a 388-110 record and led Leland to three straight Class D titles from 1980-82. He also coached the Northwestern University men’s basketball team for six seasons.
Additionally, Childress is married to past Stanford basketball star Josh Childress, who went on to play eight seasons in the NBA and several more overseas. They have three daughters, Maya, Mina and Amara.
The National High School Hall of Fame was started in 1982 by the NFHS. The 12 individuals were chosen after a two-level selection process involving a screening committee composed of active high school state association administrators, coaches and officials, and a final selection committee composed of coaches, former athletes, state association officials, media representatives and educational leaders. Nominations were made through NFHS member associations. Also chosen for this class were athletes Joe Carter (Oklahoma), Jordan Larson (Nebraska), Krissy Wendell-Pohl (Minnesota) and Patrick Willis (Tennessee); sport coaches Jan Barker (Texas), David Gentry (North Carolina) and Flo Valdez (New Mexico); game officials Burney Jenkins (Kentucky) and Mary Lou Thimas (Massachusetts), former state association administrator Steve Savarese (Alabama) and former fine arts educator Craig Ihnen (Iowa).
For more on this year’s Hall of Fame class, visit the NFHS Website.