Evaluation of Musculoskeletal Re-Injury Occurrence in Previously Concussed National Football League Athletes

Figures & data

Figure 1 Illustration of matching of SRC to MSK and control athletes, followed by reasons for injury exclusions.

Notes: Of the 683 athletes who sustained an SRC, only 186 returned to play during the third through eighth week of the regular NFL season, and 91 could be matched with appropriate MSK and healthy controls.

Abbreviations: SRC, sports-related concussion; MSK, musculoskeletal; NFL, National Football League; RTP, return to play.

Table 1 Player Demographics by Injury Type

	Total (N = 273)	SRC (N=91)	MSK (N=91)	Control (N=91)	P-value
Age in years, mean (SD)	25.99 (2.90)	25.54 (2.55)	26.07 (3.15)	26.36 (2.96)	0.15
Age range, yr	21–36	21–33	21–36	21–34
Height in meters, mean (SD)	1.87 (0.07)	1.88 (0.07)	1.87 (0.06)	1.87 (0.06)	0.43
Height range, m	1.73–2.03	1.75–2.03	1.75–2.01	1.73–2.01
Mass in kilograms, mean (SD)	108.37 (20.77)	108.24 (20.82)	108.69 (21.66)	108.17 (20.02)	0.98
Mass range, kg	77.56–154.22	77.56–149.23	79.38–154.22	78.47–152.41

Notes: One-way ANOVA comparing means of SRC, MSK, and control demographics proved to be non-significant (P > 0.05).

Abbreviations: SRC, sports- related concussion; MSK, musculoskeletal injury; yr, year; m, meters; kg, kilograms; SD, standard deviation.

Table 2 Position Type and Injury Characteristics

	Total (N=273)	SRC (n=91)	MSK (n=91)	Control (n=91)
Position, number of players (%)
Defensive Back	90 (33.0%)	30 (33.0%)	30 (33.0%)	30 (33.0%)
Linebacker	51 (18.7%)	17 (18.7%)	17 (18.7%)	17 (18.7%)
Linemen	78 (28.6%)	26 28.6%)	26 28.6%)	26 28.6%)
Running Back	12 (4.4%)	4 (4.4%)	4 (4.4%)	4 (4.4%)
Tight End	9 (3.3%)	3 (3.3%)	3 (3.3%)	3 (3.3%)
Wide Receiver	33 (12.1%)	11 (12.1%)	11 (12.1%)	11 (12.1%)
Quarterback	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Week of RTP^a, number of players (%)
2–4^b	60 (22.0%)	32 (35.2%)	28 (30.8%)	0 (0.0%)
5–6	53 (19.4%)	25 (27.5%)	28 (30.8%)	0 (0.0%)
7–9^c	69 (25.3%)	34 (37.4%)	35 (38.5%)	0 (0.0%)
No original injury	91 (33.3%)	0 (0.0%)	0 (0.0%)	91 (100.0%)
Weeks missed^d, number of players (%)
1	89 (32.6%)	45 (49.5%)	44 (48.4%)	0 (0.0%)
2	52 (19.0%)	34 (37.4%)	18 (19.8%)	0 (0.0%)
≥3	41 (15.0%)	12 (13.2%)	29 (31.9%)	0 (0.0%)
No original injury	91 (33.3%)	0 (0.0%)	0 (0.0%)	91 (100.0%)
Location of original injury, number of players (%)
Head (Concussion)	91 (33.3%)	91 (100.0%)	0 (0.0%)	0 (0.0%)
Shoulder	13 (4.8%)	0 (0.0%)	13 (14.3%)	0 (0.0%)
Arm	8 (2.9%)	0 (0.0%)	8 (8.8%)	0 (0.0%)
Chest	5 (1.8%)	0 (0.0%)	5 (5.5%)	0 (0.0%)
Hip/Pelvis	2 (0.7%)	0 (0.0%)	2 (2.2%)	0 (0.0%)
Leg	14 (5.1%)	0 (0.0%)	14 (15.4%)	0 (0.0%)
Knee	23 (8.4%)	0 (0.0%)	23 (25.3%)	0 (0.0%)
Ankle	17 (6.2%)	0 (0.0%)	17 (18.7%)	0 (0.0%)
Foot	9 (3.3%)	0 (0.0%)	9 (9.9%)	0 (0.0%)
No original injury	91 (33.3%)	0 (0.0%)	0 (0.0%)	91 (100.0%)

Notes: ^aWeek of RTP from original injury, either MSK or SRC. ^bThree athletes returning to play from MSK injuries in Week 2 were matched within one week of return to play to SRC athletes returning to play in Week 3. ^cTwo athletes returning to play from MSK injuries in Week 9 were matched within one week of return to play to SRC athletes returning to play in Week 8. ^dWeeks missed due to original injury, either MSK or SRC.

Abbreviations: SRC, sports-related concussion; MSK, musculoskeletal injury; RTP, return to play.

Figure 2 Average cumulative MSK injury occurrence for 12 weeks following RTP from original injury of SRC, MSK, or healthy controls.

Notes: SRC athletes 2.35 times more likely to sustain an MSK compared to controls. MSK athletes were 1.87 times more likely.

Abbreviations: MSK, musculoskeletal; RTP, return to play; SRC, sports-related concussion; No, number.

Table 3 Reinjury Occurrences

	Player (Co)	Injuries (Co)	Average Injuries per Player Mean (SD)	Fisher’s Exact Test^a OR(95% CI)
SRC	39	59	0.65 (0.87)	2.35 (1.25, 4.44)*
MSK	34	43	0.47 (0.67)	0.08 (0.44, 1.44)
Control	22	25	0.27 (0.52)	–
Total	95	127	0.47 (0.72)	–

Notes: ^aFisher’s Exact Test was calculated for SRC and MSK groups, respectively, against controls on the existence of any MSK injury in the 12 weeks following RTP from their original injury. *p < 0.05.

Abbreviations: Co, count; SD, standard deviation; OR, odds ratio; CI, confidence interval; SRC, sports-related concussion; MSK, musculoskeletal injury.