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.

MHSAA 2023-24 School Year Classifications Announced 

By Geoff Kimmerly
MHSAA.com senior editor

April 6, 2023

Classifications for Michigan High School Athletic Association elections and postseason tournaments for the 2023-24 school year have been announced, with enrollment breaks for postseason tournaments posted to each sport’s page on the MHSAA Website.

Classifications for the upcoming school year are based on a second semester count date, which for MHSAA purposes was Feb. 8. The enrollment figure submitted for athletic classification purposes may be different from the count submitted for school aid purposes, as it does not include students ineligible for athletic competition because they reached their 19th birthday prior to Sept. 1 of the current school year and will not include alternative education students if none are allowed athletic eligibility by the local school district.

All sports’ tournaments are conducted with schools assigned to equal or nearly equal divisions, with lines dependent on how many schools participate in those respective sports.

For 2023-24, there are 750 tournament-qualified member schools. Schools recently were notified of their classification, and sport-by-sport divisions were posted to the MHSAA Website today (April 6). MHSAA Executive Director Mark Uyl said schools may not subsequently lower their enrollment figure. However, if revised enrollment figures are higher and indicate that a school should be playing in a higher division, that school would be moved up.

Five MHSAA Finals champions awarded so far during the 2022-23 school year are assigned to different divisions for 2023-24. Division 6 champion Grand Rapids West Catholic will play 11-player football in Division 5 this upcoming season. The Holland Christian boys soccer team will be moving into Division 2 after winning the Division 3 Final in the fall, and East Grand Rapids’ girls swimming & diving program is headed back to Lower Peninsula Division 3 after winning in LP Division 2 this past season. A pair of cross country champions are on the move – LP Division 4 boys champion Wyoming Potter’s House Christian to LP Division 3, and Upper Peninsula Division 3 girls champion Munising into UP Division 2 – and the Grass Lake boys bowling team will compete in Division 3 next winter after winning the Division 4 championship last month.

Also set to change divisions among Finals runners-up from head-to-head sports are Cadillac volleyball (Division 2 to D1), Ann Arbor Greenhills boys soccer (Division 4 to D3), Mendon 8-player football (Division 2 to D1) and three 11-Player Finals runners-up – Caledonia (Division 1 to D2), Grand Rapids Forest Hills Central (Division 2 to D3) and Muskegon (Division 3 to D2).

Visit the respective sport pages on the MHSAA Website to review the divisional alignments for all MHSAA-sponsored tournament sports. Click the “SPORTS” menu above to access the page for each sport, then the “Assignments” link on the selected sport page and then “DIVISION LIST” to see the 2023-24 division.

Traditional classes (A, B, C, D) – formerly used to establish tournament classifications – are used only for MHSAA elections. To determine traditional classifications, after all counts are submitted, tournament-qualified member schools are ranked according to enrollment and then split as closely into quarters as possible. For 2023-24, there are 187 member schools in Class A, Class B and Class C, and 189 member schools in Class D.

Effective with the 2023-24 school year, schools with 807 or more students are in Class A. The enrollment limits for Class B are 380-806, Class C is 177-379, and schools with enrollments of 176 and fewer are Class D. The break between Classes A and B decreased eight students from 2022-23, the break between Classes B and C decreased 11 students, and the break between Classes C and D is six students fewer than for the 2022-23 school year.

The new classification breaks will see 21 schools move up in Class for 2023-24 while 24 schools will move down:

Moving Up from Class B to Class A
Bay City John Glenn
Fowlerville
Garden City
Lansing Eastern
Orchard Lake St. Mary’s
Tecumseh

Moving Down from Class A to Class B
Detroit Henry Ford
Detroit Mumford
Harper Woods
Plainwell
Sault Ste. Marie
Spring Lake

Moving Up from Class C to Class B
Ann Arbor Greenhills
Grand Rapids Covenant Christian
Hartford
Ishpeming Westwood
Kent City
Mason County Central
Pinconning

Moving Down from Class B to Class C
Blissfield
Clawson
Clinton Township Clintondale
Detroit Northwestern
Elk Rapids
Fennville
Sanford Meridian
Stockbridge

Moving Up from Class D to Class C
Auburn Hills Oakland Christian
Benton Harbor Countryside Academy
Detroit Crocket Midtown Science & Medicine
Grand Traverse Academy
Martin
Munising
Rudyard
Saginaw Michigan Lutheran Seminary

Moving Down from Class C to Class D
Eau Claire
Fowler
Jackson Prep
L’Anse
Marcellus
Merrill
Mesick
Morenci
Muskegon Heights Academy
St. Ignace

New Postseason-Eligible Tournament Schools in 2023-24
Waterford Oakside Prep

Enrollment Breaks by Classes – 2023-24
(Number of schools in parentheses)
Class A: 807 and above (187 schools) 
Class B: 380 – 806 (187)
Class C: 177 – 379 (187)
Class D: 176 and below (189)