TABLE 6.
Baseline Assessment Findings and Prognostic Relationships With RTP Times a
| Clinical Factors | MRI Factors |
|---|---|
| RTP Prognosis: Accelerated | |
| Pain during outer-range strength test 42 | BAMIC grade 0 61 |
| Midrange strength as % of uninjured leg 42 | Shorter radiologist-predicted time to RTP 66 |
| SLR flexibility of uninjured leg 42 | Shorter length of lesion 66 |
| Greater physiotherapy attendance 42 | Smaller injury CSA 66 |
| Shorter clinician-predicted time to RTP 66 | MRI-negative injury 9,10,33,37,62 |
| Lower grade of injury 66 | Single muscle/tendon involvement 23 |
| Sprinting-type vs stretching-type injury 10 | Lower % of muscle/tendon involvement 23 |
| Lower radiologic grade of injury 23,29 | |
| Lower Cohen MRI score 23 | |
| Injuries not involving proximal tendon 9 | |
| RTP Prognosis: No Effect | |
| Sex 43 | Craniocaudal length of injury 6,7,8,26,42,57 |
| Dominant vs nondominant limb 2,42,43 | Mediolateral width of injury 6,7,42 |
| Sudden vs gradual pain onset 42 | Depth of injury 7,30 |
| Injury during game vs training 42 | Volume of edema 7,26,57 |
| Forced to cease activity within 5 min 42 | Tendon involvement 30,42 |
| Ability to walk/jog pain-free 42 | Myofascial involvement 30,42 |
| No. of days to walk pain-free 42,57 | Muscle (most) involved 24,29,30,37,42,57,61,75,82 |
| No. of days to ascend stairs pain-free 83 | Injury CSA as % of total muscle CSA 26,42,57 |
| Mechanism of injury 2,42,57,82,83 | Distance of injury from ischium 7,8,42,57,82 |
| History of low back pain 42,82 | Intra- or intermuscular hemorrhage 66 |
| History of lower limb injury 42 | Site of injury within the muscle 23,30,61,75 |
| History of lower limb surgery 42 | Grade 1 vs grade 2 injury 29,61 |
| Pain on 1- or 2-leg squat 42 | MRI grade of injury 57 |
| Pain on palpation of injured area 35,42 | Presence of extramuscular fluid 57 |
| Craniocaudal length of palpated pain 1,6,7,42,57 | Partial disruption of the central tendon 80 |
| Mediolateral width of palpated pain 42 | Amount of central tendon retraction 80 |
| Distance of palpated pain from ischium 35,42,57 | BAMIC type a vs b 61 |
| Location of point of highest palpated pain 7,8 | |
| Site of injury within the muscle 43,55,81,83 | |
| No. of muscles injured 2 | |
| Positive vs negative slump test 82,83 | |
| Frequency of physiotherapy 2 | |
| Grade of injury 2,43 | |
| Level of play/intensity of sport 2,57 | |
| Delay in seeking physiotherapy 1 | |
| Active knee extension deficit 1,57,83 | |
| Pain upon active knee extension 57 | |
| Pain upon PKE 35 | |
| Pain on passive SLR 57 | |
| Pain upon isometric contraction 35,83 | |
| Previous ACL graft harvesting 57 | |
| Isometric knee flexion strength 5,57 | |
| Hip ROM 5,83 | |
| Use of NSAIDs within 72 h of injury 83 | |
| RTP Prognosis: Delayed | |
| Female sex 2 | Volume of injury 6,42,75 |
| Greater PKE range of uninjured leg 42 | Greater craniocaudal length of injury 9,10,23,30,66,73 |
| Greater peak torque angle in knee extension 42 | Greater width of edema 30 |
| Higher grade of injury 66 | Greater length of lesion as % of height 33 |
| Injury to biceps femoris 66 | Greater depth of injury 6 |
| Shorter distance of pain to ischium 7,9,10 | Longer radiologist-predicted time to RTP 66 |
| Stretching-type vs sprinting-type injury 5,10 | Larger injury CSA 6,33,62,66,75 |
| Greater maximum pain at time of injury 42,82 | Involvement of proximal tendon 6,10 |
| Worst VAS pain score >6 35 | Proximal vs distal injuries 6 |
| Higher VAS pain score at initial examination 81 | Shorter distance of injury to ischium 6,9,10 |
| “Popping” sound at time of injury 35 | Higher Cohen MRI score 23 /score >10 39 |
| Bruising 35 | MRI-positive injury 81 |
| Greater deficit in passive SLR 57 | Greater % of muscle/tendon involvement 23 |
| Longer clinician-predicted time to RTP 66,81 | Complete tendinous/myotendinous rupture 62 |
| Forced to cease activity within 5 min 82 | Complete central tendon disruption 24,80 |
| Greater length of palpated pain 82 | Presence of central tendon waviness 80 |
| Pain on resisted knee flexion 82 | Greater central tendon retraction 23 |
| >1 wk to initial consultation 2 | Higher radiologic grade of injury 23,29,30,37,61,82 |
| Recurrent muscle injury 2 | Greater No. of muscles involved 39 |
| Greater active knee ROM deficit 35,53 | Distal tendinous or myotendinous injury 62 |
| Longer self-predicted time to RTP 57 | Peritendinous fluid collection 62 |
| Lower level of sport 8 | |
| >1 d to walk pain-free 83 | |
a ACL, anterior cruciate ligament; BAMIC, British Athletics Muscle Injury Classification; CSA, cross-sectional area; MRI, magnetic resonance imaging; NSAID, nonsteroidal anti-inflammatory drug; PKE, passive knee extension; ROM, range of motion; RTP, return to play; SLR, straight-leg raise; VAS, visual analog scale.