Table 3.
Bivariate Analysis of Factors Associated With Having a Knee Injury During the Follow-up Period Among NBA Players
| Variables∗ | Knee Injury† |
P Value | |
|---|---|---|---|
| Yes | No | ||
| No. of players | 212 (21%) | 799 (79%) | – |
| Age, y | 26 (23-30) | 24 (22-28) | <.001 |
| Height, m | 2.0 ± 0.087 | 2.0 ± 0.086 | .16 |
| Weight, kg‡ | 100 ± 11 | 98 ± 12 | .042 |
| Body mass index‡ | 25 ± 1.7 | 25 ± 1.8 | .072 |
| Years of experience | 5 (3-9) | 2 (1-5) | <.001 |
| Follow-up duration, y | 4 (3-5) | 2 (1-3) | <.001 |
| Number of games played‡ | |||
| Total | 62 (41-73) | 41 (17-61) | <.001 |
| Regular | 58 (39-68) | 39 (16-59) | <.001 |
| Playoffs | 0 (0-6) | 0 (0-3) | .20 |
| Minutes per game‡ | |||
| Total | 24 (18-30) | 14 (8-20) | <.001 |
| Regular | 25 (18-30) | 14 (9-20) | <.001 |
| Playoffs | 0 (0-19) | 0 (0-6) | .080 |
| Performance metrics | |||
| Usage rate | 19 (16-24) | 17 (14-20) | <.001 |
| Player efficiency rating | 14 (11-17) | 11 (7.9-14) | <.001 |
| True shooting percentage | 0.55 (0.51-0.59) | 0.52 (0.47-0.57) | <.001 |
| Points per game | 9.2 (6.1-14) | 4.6 (2.6-7.7) | <.001 |
| Block percentage | 0.40 (0.20-0.66) | 0.20 (0.090-0.40) | <.001 |
| Total rebound percentage | 3.9 (2.5-5.3) | 2.2 (1.3-3.5) | <.001 |
| Position | .481 | ||
| Point guard | 48 (23%) | 155 (19%) | |
| Shooting guard | 42 (20%) | 200 (25%) | |
| Small forward | 36 (17%) | 147 (18%) | |
| Power forward | 45 (21%) | 156 (20%) | |
| Center | 41 (19%) | 141 (18%) | |
| Games missed due to injury | 3 (1-10) | 1 (0-4) | <.001 |
| Other lower-extremity injury§ | 173 (82%) | 355 (44%) | <.001 |
| Foot | 56 (26%) | 73 (9.1%) | <.001 |
| Ankle | 109 (51%) | 223 (28%) | <.001 |
| Calf or shin | 68 (32%) | 102 (13%) | <.001 |
| Hip, hamstring, or quadriceps | 112 (53%) | 176 (22%) | <.001 |
NBA, National Basketball Association.
Continuous variables presented as mean ± standard deviation or as median (interquartile range); discrete variables as the number of patients, with the percentage in parentheses. Values in bold indicate statistical significance at P < .05. All variables with P < .10 were moved to multivariable analysis.
Includes any type of structural injury (e.g., fracture, ligament sprain, strain, or rupture) and nonspecific symptoms (e.g., bruising, or effusion). Knee soreness alone was excluded from analysis. One player with a gunshot wound to the knee was excluded from analysis.
Only weight was moved to multivariable regression because of expected multicollinearity with body mass index; only “total number of games played” and “total minutes per game” were moved to multivariable analysis.
Includes any type of hip, upper and lower leg, foot, or ankle injury.