Table 5 Candidate prognostic factors—exploration

Anthropometric

Height

No

Centimetres

Standing height measure

Continuous

–

Weight

No

Kilograms

Digital scales

Continuous

–

Medical history

Frequency of previous foot or ankle injuries within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous foot or ankle injury within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous hip or groin injuries within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous hip or groin injury within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous knee injuries within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous knee injury within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous shoulder injuries within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous shoulder injury within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous lumbar spine injuries within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous lumbar spine injury within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous iliopsoas IMIs within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous iliopsoas IMI within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous adductor IMIs within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous adductor IMI within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous hamstring IMIs within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous hamstring IMI within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous quadriceps IMIs within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous quadriceps IMI within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Frequency of previous calf IMIs within 3 years prior to PHE

No

Freq.

Medical records

Continuous

–

Most recent previous calf IMI within 3 years prior to PHE

No

< 6 months, 6–12 months, > 12 months

Medical records

Categorical

–

Musculoskeletal

Mean PROM hip joint internal rotation**

Yes

Degrees

Digital inclinometer

Continuous

Intra-rater ICC = 0.90 [37]

Mean PROM hip joint external rotation**

Yes

Degrees

Digital inclinometer

Continuous

Intra-rater ICC = 0.90 [37]

Mean hip flexor muscle length**

Yes

Degrees

Digital inclinometer - Thomas test

Continuous

Inter-rater ICC = 0.89 [38]

Mean hamstring muscle length/neural mobility**

Yes

Degrees

Digital inclinometer - SLR

Continuous

Intra-rater ICC = 0.95–0.98 [40]

Inter-rater ICC = 0.80–0.97 [40]

Mean calf muscle length**

Yes

Degrees

Digital inclinometer - WBL

Continuous

Inter-rater ICC = 0.80–0.95 [41, 42]

Intra-rater ICC = 0.88 [42]

Strength/power

Maximal loaded leg extension power difference*

Yes

Normalised watts per kilo (W/kg^−0.67)

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.886 [46]

Mean of maximal loaded leg extension power**

Yes

Normalised watts per kilo (W/kg^−0.67)

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.886 [46]

Loaded maximal leg extension velocity difference*

Yes

Peak velocity (m s⁻¹)

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.792 [46]

Mean of maximal loaded leg extension velocity**

Yes

Peak velocity (m s⁻¹)

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.792 [46]

Loaded maximal leg extension force difference*

Yes

Normalised peak force (N/kg^−0.67 )

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.914 [46]

Mean of maximal loaded leg extension force**

Yes

Normalised peak force (N/kg^−0.67)

Double leg press test using a Keiser Air 300 machine

Continuous

Test-retest ICC = 0.914 [46]

CMJ force per kilogram of body mass

No

Force per kg (N/kg)

CMJ using force plates

Continuous

–

CMJ height

No

Centimetres

CMJ using force plates

Continuous

Test-retest ICC = 0.80–0.88 [47]