Risk factors for ERLP in a military setting
| Factor | Unfavourable characteristic | Reference | Year | Country | Cohort | Gender of participants | Outcome statistics |
|---|---|---|---|---|---|---|---|
| Gender | Female | 4 | 2004 | Australia | Navy | 84 M; 40 F | RR for MTSS 2.03 |
| 11 | 2013 | USA | All forces | 4100 | RR for CECS 1.11; 95% CI 1.05 to 1.14 | ||
| 12 | 2013 | NED | Premilitary | 1478 M; 115 F | ERLP 9.3% of M; 16.5% of F | ||
| 13 | 2004 | Australia | Cadets | 122 M; 36 F | OR for medial tibial pain 3.1 | ||
| 14 | 2012 | Australia | Cadets | 288 M; 96 F | OR for MTSS 2.97; 95% CI 1.66 to 5.31 | ||
| 15 | 1993 | USA | Army BMT | 124 M; 186 F | OR for lower extr. 2.1; 95% CI 1.5 to 3.1 | ||
| Current status | Tenderness to palpation medial tibial border | 14 | 2012 | Australia | Cadets | 288 M; 96 F | OR for MTSS 4.63; 95% CI 2.5 to 8.5 |
| Oedema (very unfavourable) | 14 | 2012 | Australia | Cadets | 288 M; 96 F | OR for MTSS 76.1; 95% CI 9.6 to 602.7 | |
| Foot shape | Increased navicular drop >0.5 cm | 16 | 2010 | NED | Recruits | 35 M | Univariate regr 12.7; 95% CI 1.3 to 121.5 |
| Reduced navicular drop <0.422 cm | 17 | 2015 | Iran | Recruits | 181 | p=0.015 | |
| Pronated foot (foot posture index≥+6) | 4 | 2004 | Australia | Navy | 84 M; 40 F | RR for MTSS 1.70 | |
| High foot arch (bony arch index >0.23) | 18* | 1999 | USA | Navy | 449 M | RR 1.71; 95% CI 0.74 to 3.95 | |
| >0.27 | 19 | 1993 | USA | Infantry | 246 M | OR 6.12; 95% CI 2.17 to 17.30 | |
| Low foot arch (bony arch index <0.20) | 18* | 1999 | USA | Navy | 449 M | RR 1.86; 95% CI 0.82 to 4.25 | |
| Hip function | Large exorotation >64°, only in men | 13 | 2004 | Australia | Cadets | 122 M; 36 F | Right hip p=0.026; Left hip p=0.042 |
| >60° | 20* | 1991 | Israel | Army | 289 M | p<0.001 | |
| Restricted exorotation <41° | 17 | 2015 | Iran | Recruits | 181 | p=0.000 | |
| Large endorotation >48°, only in men | 13 | 2004 | Australia | Cadets | 122 M; 36 F | Right hip p=0.014; Left hip p=0.000 | |
| Restricted endorotation <40° | 16 | 2010 | NED | Recruits | 35 M | Univariate regr 1.1; 95% CI 1.0 to 1.2 | |
| <37° | 17 | 2015 | Iran | Recruits | 181 | p=0.004 | |
| Leg circumference | Lean calf girth <34 cm, only in men | 13 | 2004 | Australia | Cadets | 122 M; 36 F | Right leg only, p=0.040 |
| Narrow tibial bone width <25 mm | 20* | 1991 | Israel | Army | 289 M | p<0.001 | |
| Ankle function | Dorsal flexion ≥21° | 21 | 2010 | USA | Marine Corps | 748 F | OR for shin splints 3.4; 95% CI 1.4 to 8.4 |
| Plantar flexion >52° | 16 | 2010 | NED | Recruits | 35 M | Univariate regr 0.8; 95% CI 0.7 to 1.0 | |
| Other biometrics | Iliospinal height >53 cm | 17 | 2015 | Iran | Recruits | 181 | p=0.017 |
| Lateral trochanter-tibia height >44.69 cm | 17 | 2015 | Iran | Recruits | 181 | p=0.022 | |
| Target job | Soldier (lower rank) | 11 | 2013 | USA | All forces | 4100 | RR for CECS 8.54; 95% CI 7.04 to 10.36 |
| 22 | 2011 | GB | Infantry | 660 M | HR officers 0.26; 95% CI 0.14 to 0.49 | ||
| Target force | Army | 11 | 2013 | USA | All forces | 4100 | RR for CECS 2,72; 95% CI 2.45 to 3.04 |
| Walking technique | Overpronation (foot balance concept) | 23 | 2011 | GB | Infantry | 468 M | OR for MTSS 9.16; 95% CI 4.32 to 19.42 |
| Foot pressure measurement barefoot, cavus | 18* | 1999 | USA | Navy | 449 M | RR for stress # 1.7; 95% CI 0.59 to 4.89 | |
| Foot pressure measurement barefoot, planus | 18* | 1999 | USA | Navy | 449 M | RR for stress # 2.18; 95% CI 0.80 to 3.98 | |
| Foot pressure measurement barefoot | 24 | 2014 | GB | Navy officers | 200 M | OR for OLLI 5.28; 95% CI 2.88 to 9.70 | |
| Foot pressure measurement shod, cavus | 18* | 1999 | USA | Navy | 449 M | RR for stress # 1.82; 95% CI 0.63 to 5.24 | |
| Foot pressure measurement shod, planus | 18* | 1999 | USA | Navy | 449 M | RR for stress # 2.45; 95% CI 0.89 to 6.70 | |
| Heavy heel strike | 23 | 2011 | GB | Infantry | 468 M | OR for MTSS 9.16; 95% CI 4.32 to 19.42 | |
| Running technique | Overpronation | 25 | 1993 | No statistics | |||
| Blood | Low vitamin D intake (<118 IU, <70.0 nmol/L) | 26* | 2012 | Israel | Combat recruits | 74 M | Stress # group 59% of DRI (p<0.05) |
| Low vitamin D in blood <75.8 nmol/L | 27* | 2006 | Finland | Recruits | 756 M | OR for stress # 3.6; 95% CI 1.2 to 11.1 | |
| History | Previous lower limb injury | 23 | 2011 | GB | Infantry | 660 M | HR for all injuries 1.49; 95% CI 1.19 to 1.87 |
| Menstrual dysfunction >1 year | 28* | 2006 | USA | Marine Corps | 2962 F | OR for all stress # 5.64; 95% CI 2.2 to 14.4 | |
| Lower extremity stress fracture | 29* | 2006 | USA | Marine Corps | 824 F | OR for stress # 2.1; 95% CI 0.8 to 5.5 | |
| Fitness | >650 s on a 2.4 km run | 23 | 2011 | GB | Infantry | 468 M | OR for MTSS 3.62; 95% CI 1.77 to 7.38 |
| Average or lower premilitary activity level | 30* | 1988 | USA | Marine recruits | 3025 | RR 2.4; 95% CI 1.26 to 4.58 | |
| Low self-rated fitness | 29 | 2006 | USA | Marine Corps | 824 F | OR for OLLI 1.6; 95% CI 1.1 to 2.5 | |
| Smoking | Smoker | 23 | 2011 | GB | Infantry | 468 M | OR for MTSS 6.54; 95% CI 3.09 to 13.82 |
*Risk factor specifically for stress fracture.
BMT, basic military training; CECS, chronic exertional compartment syndrome; ERLP, exercise related leg pain; extr, extremity injury; GB, Great Britain; MTSS, medial tibial stress syndrome; NED, Netherlands; OLLI, overuse lower limb injury; OR, odds ratio; regr, regression; RR, relative risk.