Summary of the assessment items that were candidates for the regression analyses, and the results
| Assessment item | Retained in initial examination regression analysis? | Retained in week 1 regression analysis? |
|---|---|---|
| Injury and patient history | ||
| Date of injury and today's date (to calculate delay in presentation) | No | Yes (days delay) |
| Sport played | If volleyball | If football |
| Side injured and limb dominance | No | No |
| Onset of pain—sudden or gradual | No | No |
| Pain local to hamstring only or referred | No | No |
| Injury incurred during game or training | No | No |
| Was the athlete forced to stop within 5 min? | No | No |
| Was the athlete able to keep running after the injury? | No | No |
| Could the athlete walk pain free immediately? | No | No |
| How many days until the athlete was able to walk pain free? | No | Yes |
| Mechanism of injury (sprinting, kick, tackle, stretch or other) | No | No |
| Was the injured leg weight-bearing at the time of injury? | No | No |
| Maximum pain at the time of injury? (0–10) | No | No |
| Maximum pain today (day of assessment) (0–10) | Yes | Yes |
| Previous history of hamstring injury to this leg or the other leg? If yes, include duration of absence from sport. | If both legs had previously had a hamstring injury | |
| History of low back pain? | No | No |
| History of knee injury on this leg or the other leg? | No | No |
| History of groin injury to this side or the other side? | No | No |
| History of calf injury to this side or the other side? | No | No |
| History of other injuries not specified above? | No | No |
| History of surgery? | No | No |
| Physical examination of current injury | ||
| How far can the athlete forward flex while standing (knee, mid shin, ankles, floor) and do they have pain limiting? | No | No |
| Can the athlete walk without pain and/or a limp? | No | No |
| Can the athlete jog without pain and/or a limp? | No | No |
| Is there any pain on a 2 leg half squat? | No | No |
| Is there any pain on a 1 leg quarter squat? | No | No |
| Is the pain on palpation of the injured area nil, mild, or marked? | No | No |
| What is the length (in cm) of pain craniocaudally on palpation? | No | No |
| What is the width of pain (in cm) medial-laterally on palpation? | No | No |
| What is the distance from the ischium (in cm) of the most proximal aspect of the patient's pain? | No | No |
| What is the strength (in kg) of both, the injured and uninjured leg on the ‘inner’, ‘mid’ and ‘outer’ range tests? | Mid range strength expressed as a percentage of the uninjured leg | Change in strength for the mid range test in the first week; inner range strength on day 1; outer range strength as a percentage at day 7 |
| Is there pain on any of these strength tests, if so, on which? | Pain on outer range strength test at day 1 | If the outer range test is painless at day 7 |
| What is the range of motion (in degrees) for: Straight Leg Raise, Passive Knee Extension in 90° hip flexion and Active Knee Extension in maximum hip flexion? | Straight leg raise; Passive knee extension range on the uninjured leg | No |
| Is there any pain on any of these tests, if so, on which? | No | No |
| Can the athlete perform 3 repetitions of a single leg bridge on a 1 m step painlessly? If not, how close can he get—3 repetitions on the bed with 1 leg, 3 repetitions with 2 legs, 2 legs partial movement, or only reaching the starting position? | No | If the athlete can do the single leg bridge painlessly at day 7 |
| Isokinetic evaluation of the uninjured leg recording peak torque and angle of peak torque for knee flexion and extension at 60°/s, 300°/s concentric, and 60°/s eccentric (knee flexion only) | Angle of peak torque for knee extension at 60°/s | Peak torque for knee flexion at 60°/s, concentric |
| MRI variables: volume of oedema, craniocaudal length of oedema, medial-lateral length, tendon involvement, myofascial involvement, muscle involved, per cent involvement compared to entire muscle, distance to ischium of most proximal part of injury | No | No |
Where indicated, the individual assessment item was included in the equation for predicting return to play at either day 1 or day 7—that is, this item was clinically useful in predicting return to play duration, otherwise it was not. Findings which were associated with return to sports are emphasised in bold typeface.