Background
Methods
Part 1 Identification of biomechanics assessment protocols used in practice
Part 2 Evaluation of the inter-assessor reliability of the biomechanical assessment protocol
Biomechanical examination | Method |
---|---|
Neutral calcaneal stance position (NCSP) and relaxed calcaneal stance position (RCSP) | (i) Participant standing (ii) Position both feet into NCSP (iii) Pen marker bisection line drawn onto the posterior aspect of the calcaneus on both feet (iv) Measurement recorded using digital biometer for right foot (v) Identify if calcaneus is positioned varus or valgus (vi) Repeat procedure with left foot (vii)Both feet resume RCSP, measurement of the bisection line using a digital biometer for both feet |
Range of ankle joint dorsiflexion | (i) Participant supine and sitting with back straight against plinth (ii) A straight reference line is drawn onto the lateral aspect of leg indicating where one of the tractograph arms should be positioned (iii) Tractograph is positioned with one lever arm running parallel to the lateral aspect of leg and the other positioned parallel to the plantar aspect of the foot running distally (iii) With the knee joint extended, the foot is maximally dorsiflexed and the measurement on the tractograph recorded (iv) The knee joint is held in a flexed position, the ankle joint is maximally dorsiflexed and the measurement on the tractograph recorded (v) Repeat procedure with other foot |
Position and mobility at the first ray | (i) Participant supine and sitting with back straight against plinth (ii) First ray position classification (dorsiflexed/plantarflexed or neutral) (iii) First ray mobility classification (flexible/rigid/normal) (iv) Repeat procedure with cother foot |
Forefoot to rearfoot relationship (frontal plane) | (i) Participant prone, lying down (ii) Raise one side of pelvis from couch with a cushion/pillow, so that the long axis of the contra lateral foot is vertical (iii) Position the foot in subtalar joint neutral (iv) Visually observe position of forefoot relative to rearfoot. Categorise if neutral/everted/inverted.(v) Repeat procedure with other foot |
Range of motion at the first MTPJ | (i) Participant supine and sitting with back straight against plinth with legs extended in front (ii) Place arms of the goniometer parallel to the long axis of the first metatarsal and the proximal phalanx of the hallux (iii) Manually dorsiflex first MTPJ with first ray free to move and measure range of motion with goniometer (iv) Repeat stage 3, with first ray held in a neutral position (v) Repeat procedure with left foot |
Foot Posture Index | The 6 Point FPI is to be used and follows the protocol described by Redmond et al. [31] |
Limb length examination | (i) Participant standing in RCSP (ii) Both ASIS are palpated, identification of whether a limb length discrepancy is present (iii) Classification of which leg is longer and whether this is less than 5 mm, more than 5 mm or more than 10 mm |
Visual gait analysis | On conducting a clinical gait analysis, key determinants to be observed (i) Position of foot at heel strike (ii) Forefoot and midfoot position during loading phase. (iii) Foot position and motion during propulsion and re-supination (iv) Movement of the foot and leg during swing phase (v) Motion of the hip and knee (vi) Timing and magnitude of motion |
Statistical analysis
Results
Part 1
Biomechanical examination | No. of podiatrists that use the assessment (total =12) | Key features of examination (derived from questionnaire) | Consensus from group discussion |
---|---|---|---|
NCSP and RCSP | 9 | Position is estimated not measured 9/9 Use this as an assessment of foot type 8/9 Use this to develop a treatment rationale (for example orthotic prescription) | Frontal plane position of the calcaneus relative to the leg was always observed Foot type is classified as pronated/supinated/neutral This is a key biomechanical examination of the foot Heel bisection lines do not add value to the examination Podiatrists feel that they could accurately measure the frontal plane position of the calcaneus quantitatively if required |
Range of motion at the ankle joint | 12 | Range of motion is estimated, not measured 12/12 podiatrists assessed with the knee extended 9/12 podiatrists assessed with the knee flexed The total range of motion and range of dorsiflexion are assessed | Podiatrists state that the normal range of ankle dorsiflexion is 10° Assessment of the range of motion is based on the podiatrist's own experience as to what they perceive as normal and not through the use of a goniometer/other measuring device Podiatrists feel that they could accurately measure the range of ankle joint dorsiflexion quantitatively if required |
Range of motion at the subtalar joint | 11 | Motion is estimated not measured Subtalar joint neutral (non weight-bearing) is used as a reference position to determine the amount of pronation and supination | Podiatrists believe that this examination is a good indicator of dynamic foot function, but it is difficult to conduct |
Position and mobility of the first ray | 11 | Position and mobility are estimated not measured 9/12 use categorical rather than numerical data | Consensus from podiatrists was that for examination of first ray mobility and position categorical data (e.g. “rigid/flexible/normal”) is more useful than numerical data |
Forefoot to rearfoot relationship | 11 | Position is estimated not measured. 11/11 use this assessment in the frontal plane only | No consensus on what should be used to define the forefoot (e.g. use middle three metatarsals or use all five metatarsals) |
Range of motion at the first MTPJ | 11 | Motion is estimated not measured 9/12 assess the total range of motion of the first MTPJ 6/12 assess the range of first MTPJ dorsiflexion | Consensus from podiatrists was that assessment of the forefoot was dependent on the presenting musculoskeletal complaint/injury and their focus was always on the function of the rearfoot |
Foot Posture Index (FPI) [31] | 6 | 6/12 use the FPI as an assessment of foot type/posture | Some podiatrists were unaware of the FPI Some podiatrists did use individual elements of FPI |
Assessment of the lower limb | 12 | All podiatrists assess the lower limb, leg and foot | Podiatrists state that it is important to assess the pelvis, lower limb, leg and foot in a biomechanical assessment |
Leg length discrepancy examination | 7 to 9 | Limb length is estimated not measured 9/12 assess anatomical limb length 7/12 assess functional limb length | Consensus from podiatrists was that the examination of limb length is important and a limb length discrepancy is a common cause of abnormal biomechanical function of the foot, leg and lower limb Podiatrists feel that the process of obtaining a precise measurement (through tape measure) is not reliable and instead categorise the leg length discrepancy, for example <5 mm, <10 mm, >10 mm Measurement of limb length should also involve shoulder tilt, ASIS symmetry (supine and standing) |
Additional biomechanical examinations | NA | Examination of internal and external hip rotation Examination of hamstring flexibility (Straight leg raise test) "Heel raise" test to assess function of tibialis posterior | Podiatrists state that these are not mandatory examinations and therefore are only used for specific clinical presentations |
Gait Analysis | 11 | 11/11 assess the dynamic function of the foot, ankle and knee 10/11 assess the dynamic function of the hip and upper body | Dynamic assessment is as important as static examination for diagnosis and development of a treatment plan |
Key determinants of the gait cycle to be observed during a routine gait analysis | NA | Position of foot at heel strike Forefoot and midfoot position during loading phase.Foot position and motion during propulsion and re-supination Movement of the foot and leg during swing phase Motion of the hip and knee Timing and magnitude of motion 4 to 6/12 podiatrists had access to gait analysis equipment e.g. pressure plate, 2D video analysis | Podiatrists state that they follow a relatively consistent protocol when conducting a clinical gait analysis assessment. The protocol involved identifying foot function at key events during the gait cycle and always aiming to analyse these from a visual perspective Consensus among podiatrists was that they would compare the dynamic function of a patient’s foot and ankle to the description of “normal” they were taught at undergraduate level, the predominant basis for this was Root et al. [3, 4] The consensus among podiatrists was that additional gait analysis equipment did not aid their assessment or treatment plan. All podiatrists felt they were confident in their visual analysis of the patient walking and what was feasible within the time constraints |
Part 2
ICC values for RCSP and NCSP
| ||
RCSP (ICC 2’1) | NCSP (ICC 2’1) | |
Right foot | 0.23 | 0.14 |
Left foot | 0.14 | 0.11 |
ICC values for the range of ankle joint dorsiflexion | ||
Knee extended | Knee flexed | |
Right foot | 0.44 | 0.61 |
Left foot | 0.42 | 0.51 |
Fleiss Kappa values for categorisation of first ray position and mobility | ||
First ray position | First ray mobility | |
Right foot | −0.03 | 0.05 |
Left foot | 0.01 | −0.01 |
Fleiss Kappa values for the categorisation of limb length examination | ||
Identification of longer leg | Identification of longer leg length | |
Limb length examination | 0.02 | 0.02 |
Foot | Examination | Mean (°) | SD (°) | Range (°) | 95 % CI (°) |
---|---|---|---|---|---|
Right foot | RCSP | 0.2 | 3.2 | 11.2 | −2.0 to 2.6 |
NCSP | 3.4 | 3.6 | 12.2 | 0.9 to 5.8 | |
Left foot | RCSP | −0.4 | 3.4 | 11.2 | −2.7 to 1.9 |
NCSP | 3.2 | 2.8 | 8.8 | 1.2 to 4.9 | |
Results of random effects ANOVA | |||||
√Estimate of covariance parameter (°) | |||||
Foot | Examination | √E random error (°) | √E ¹ assessor error (°) | √E ² subject error (°) | Total (°) |
Right foot | RCSP | 3.2 | 0.6 | 1.8 | 3.8 |
NCSP | 2.2 | 2.9 | 0.8 | 3.8 | |
Left foot | RCSP | 4.9 | 3.4 | 1.1 | 9.5 |
NCSP | 2.2 | 1.8 | 1.0 | 3.1 |
Foot | Examination | Mean (°) | SD (°) | Range (°) | 95 % CI (°) |
---|---|---|---|---|---|
Right foot | Knee Extended | 3.9 | 7.0 | 23.0 | −0.8 to 8.6 |
Knee Flexed | 10.5 | 7.3 | 23.0 | 5.6 to 15.5 | |
Left foot | Knee Extended | 3.0 | 6.6 | 20.5 | 0.1 to 9.1 |
Knee Flexed | 7.5 | 6.9 | 22.2 | 5.2 to 14.2 | |
Results of random effects ANOVA | |||||
√Estimate of covariance parameter (°) | |||||
Foot | Examination | √E random error (°) | √E ¹ assessor error (°) | √E ² subject error (°) | Total error (°) |
Right foot | Knee Extended | 5.2 | 4.9 | 4.6 | 10.7 |
Knee Flexed | 4.5 | 5.8 | 5.7 | 9.3 | |
Left foot | Knee Extended | 4.9 | 4.6 | 4.3 | 8.0 |
Knee Flexed | 5.1 | 4.9 | 5.2 | 8.7 |
Percentage agreement values | ||||
---|---|---|---|---|
Foot | Examination | Plantarflexed (%) | Neutral (%) | Dorsiflexed (%) |
Right foot | First ray position | 55.0 | 31.5 | 13.5 |
Left foot | 62.0 | 30.0 | 8.0 | |
Flexible (%) | Neutral (%) | Rigid (%) | ||
Right foot | First ray mobility | 94.0 | 1.5 | 4.5 |
Left foot | 91.0 | 7.0 | 2.0 |
Percentage agreement values | ||||
---|---|---|---|---|
Examination | Right (%) | Left (%) | None (%) | |
Identification of longer leg | 64.0 | 12.0 | 24.0 | |
up to 5 mm (%) | 5-10 mm (%) | greater than 10 mm (%) | None (%) | |
Identification of longer leg length | 23.0 | 39.0 | 14.0 | 24.0 |