Acceleration Test 10 / 20 m

Why it matters

A stopwatch tells you how fast. VueMotion shows how.

Every Acc test gives you three layers on top of the time. Together they turn one sprint into decisions for performance, injury risk, return to play, benchmarking and scouting.

Step Quality

The first six steps scored on propulsion, coordination and contact, against age, sex, sport and cohort norms.

Sprint quadrant

Bounder, Strider, Bouncer or Spinner. The quadrants come from research on acceleration technique, so they fit this test directly.

Speed, acceleration & symmetry

Splits, max speed and max acceleration, plus left–right step length, frequency, contact and flight time.

Performance monitoring

Is the athlete's start getting quicker, holding steady, or fading?

Time & speed 0–5 / 5–10 splits, max speed and max acceleration vs previous best and cohort norms.
Step Quality Total score (%) and the six-step averages tracked each session, not just the finish time.
Quadrant A shifting position shows the acceleration strategy is changing, for better or worse.

Performance improvement

Which part of the start should we coach?

Propulsion Speed at toe-off and step length show whether each push is building speed. Pushing force more horizontally is a key determinant of sprint acceleration (Morin et al., 2011).
Coordination Thigh separation at toe-off and knee separation at touchdown show how well the limbs switch.
Contact Contact distance shows if the foot lands too far ahead of the hip and brakes the athlete.

Injury risk reduction

Who accelerates in a way linked to hamstring or calf injury?

Quadrant In professional rugby, players with a high step-rate / short flight-time acceleration strategy (Spinners) were over 2.5× more likely to sustain hamstring injuries, and long step / long flight (Bounders) over 2.5× more likely to sustain calf injuries (Wild & Bezodis).
Contact Landing far ahead of the hip adds braking at the moment the hamstrings are most loaded.
Asymmetry Big left–right gaps in contact time or step length point to overload on one side.

Safer, faster return to play

Can the athlete accelerate like they did before injury?

Baseline match Compare splits, max acceleration and each of the first six steps with the athlete's own pre-injury test.
Step by step See exactly where the injured side still differs: a shorter push, a longer contact or a braking touchdown.
Strategy check Confirm the athlete hasn't shifted into a different quadrant to protect the injury.

Benchmarking

How does the athlete's start compare with their peers?

Cohort norms Every metric is compared with athletes of the same sport, sex, age and level: Effective (> +2%), Monitor (±2%) or Attention (< −2%).
Normative range The first-six-step averages (speed at toe-off, step length, thigh and knee separation, contact distance, leg stiffness) against age, sex, sport and cohort.
Squad view Rank the squad on splits, max acceleration and quadrant to set standards by position and track the group over a season.

Scouting & talent ID

Who is explosive over the first steps, and who can improve most?

Objective speed Calibrated 0–5 / 5–10 splits and max acceleration from one iPhone: comparable across trials, venues and recruits, unlike hand timing.
Step Quality Quick athletes with low propulsion or contact scores have untapped potential that coaching can unlock.
Profile fit The quadrant shows each recruit's acceleration strategy and its injury profile before you sign or select.

Quadrants and step-quality metrics describe movement patterns linked to performance and injury in research. They support coaching and clinical judgement; they do not diagnose or predict an individual injury.

01 · Setup

The 5-cone setup and camera position

Five cones mark a 1.22 m lane, with the start, halfway and finish lines on one side and the start and finish lines on the other. The athlete starts still with the front foot just behind the start line; the clock starts when the back foot leaves the ground.

Cones (9 in)Camera field of viewTiming linesFront camera (optional)Footprints get longer as speed builds

Sagittal camera

Front camera (optional add-on)

About 5 m beyond the nearest exit (finish) cones, in line with the lane and facing the athlete, at the same height as the sagittal camera (1.5 m), in portrait with 3× zoom on the athlete. Record both phones in sync with Controller-Capture. The front view adds coronal (frontal-plane) angles at the synchronised touchdown and toe-off events, such as knee alignment (FPPA), pelvic drop, trunk side lean and step width. Safety first: the athlete must be able to slow down well before reaching the camera; move it further back if they need more room.

⏱

Timing

The clock starts when the athlete's back foot leaves the ground (STF), splits when the chest crosses the halfway cone (MTF) and stops when the chest crosses the finish line (ETF).

▶

Standing start

Front foot just behind the start line, back foot visible in the camera view (inside the buffer). No rolling or flying start. Runs can go left-to-right or right-to-left.

Start recording before the athlete moves and stop after they cross the finish line. Other athletes should queue outside the camera's view. Supported distances: 10–20 m or yd.

02 · Capture

Record in about five minutes

Equipment

iPhone 11 or newer, tripod, five 9-inch yellow cones and a measuring tape (10 m minimum).

Camera

Tripod side-on at 1.5 m height, landscape, 1× lens, with the whole zone and both buffers in frame. Optional front camera: about 5 m past the exit cones, 1.5 m high, portrait, 3× zoom, synced with Controller-Capture.

Cones

Lay out the 5-cone zone: 10 or 20 m long, 1.22 m wide, with a halfway cone.

Tag + record

Choose the test tag (VM-Acc-10-m, VM-Acc-20-m, VM-Acc-10-yd or VM-Acc-20-yd) and the athlete, then record.

Upload

In the app, Select → Select all → Upload All, then submit the AI request from the Cloud screen.

Camera settings (important)

4K at 60 fps. At least 50 fps is needed for step-quality metrics
Outdoor mode outdoors; indoor mode with a fast shutter (S = 1/500) indoors
Auto-FPS off (Settings → Camera → Record Video)
Do Not Disturb on, Auto-Lock never

Athlete

Full warm-up guided by a coach, finishing with a few build-up starts
Front foot just behind the line, back foot in view
Start still: no rocking or rolling start
Sprint all the way through the finish line

Scene & upload tips

Bright, even light; avoid a light source facing the camera
Clothing should contrast with the background
Upload the original file from the VueMotion app; AirDrop, Photos exports and messaging apps can change the frame rate
Missing tags? Email support@vuemotion.com

03 · What the camera sees

The first six steps, one by one

Markerless pose tracking follows the athlete from the first push. For each of the first six steps VueMotion captures the toe-off (the push) and the touchdown (where the foot lands), and measures the angles that drive acceleration.

STEP 1 · TOE-OFF

Stick-figure kinogram frame with joint angles

Toe-off

Real stick-figure kinogram frames from a 10 yd Acc test, with joint angles as they appear in your results. The frames play in time order (toe-off, touchdown, next step); tap a step or event to hold it.

In your results: kinograms in three views

Toe-off (top row) and touchdown (bottom row) for each of the first six steps, with the video frame number on each tile. (Example: 10 yd Acc; faces blurred.)

Kinogram panel: toe-off and touchdown for the first six steps

Step quality: propulsion, coordination and contact

The PDF report's Step Quality page scores the first six steps on the three components of acceleration and combines them into a total score (%). The Normative Range page compares the six-step averages against age, sex, sport and cohort. It needs video recorded at 50 fps or more. (Example: 10 yd Acc.)

Total step-quality score · example

57 %

0%100%

Propulsion: how well the athlete builds horizontal momentum.
Coordination: how well the limbs switch at speed.
Contact: how efficiently the foot meets the ground.

Metric	1	2	3	4	5	6	Avg

Linking step quality to injury risk

The strongest injury evidence for acceleration is the sprint quadrant: Wild & Bezodis followed 85 professional rugby players for seven seasons and linked acceleration strategy to hamstring and calf injury (see section 05). No study has yet tested the individual step-quality metrics as injury predictors, so use them to explain the athlete's strategy and to track change.

Metric	Link to performance or injury	Evidence

Direct tested against injury in acceleration Performance linked to sprint performance Mechanistic biomechanical rationale only Mixed conflicting evidence

04 · Outputs

What you get after upload

Key metrics

0–5 / 5–10 splits, total time, average and max speed, max acceleration, plus left/right step length, frequency, contact and flight time.

Step quality (first 6 steps)

Speed at toe-off, step length, thigh separation, knee separation, contact distance and leg stiffness for every step, with a total score.

Normative range

Six-step averages compared with athletes of the same age, sex, sport and cohort.

Kinograms + AR video

Toe-off and touchdown for each of the first six steps in three views, and AR video with step length and instantaneous speed.

Motor preference

Sprint quadrant from cohort z-scores, with left and right legs and a max-speed band.

Graphs

Hip displacement, ground contact time, step frequency, air time, instantaneous speed and acceleration.

PDF report

Splits and max speed vs previous and all-time best, asymmetry, step quality, kinograms, normative range, progress and improvement advice.

Front view (optional)

With the front camera: coronal angles at synchronised touchdown and toe-off, such as knee alignment (FPPA), pelvic drop, trunk side lean and step width.

CSV / API

CSV/Excel export for Enterprise and Academy users; API access for Enterprise.

Interactive results dashboard

Data ViewRadarPDF ReportKinogramMotor Pref

Data View lists every metric against population norms, grouped as Effective (better than norm by more than 2%), Monitor (within ±2%) or Attention (behind by more than 2%), with a written session overview. The Kinogram tab shows the six steps in all three views with the step-quality table underneath.

Metric definitions

Timing, speed and acceleration

STF: Start Trip Frame: the last frame where the back foot is on the ground (its toe-off). The clock starts here.
MTF · ETF: Mid and End Trip Frames: the chest crosses the halfway and finish cones.
CD · HCD: Calibration Distance (10 or 20 m/yd) and half of it.
Time 0–HCD / HCD–CD: STF → MTF and MTF → ETF (e.g. 0–5 and 5–10 yd).
Total time 0–CD: STF → ETF.
Average speed: CD ÷ total time (m/s or ft/s, with km/h or mph).
Maximum speed: Highest speed between STF and ETF, over 0.25 s intervals then smoothed.
Maximum acceleration: Highest rate of speed increase during the run (m/s²).

Step metrics

Step length: Forward distance between the toe-offs of the current and previous step. The first step is skipped in averages because it is measured from the start position.
Ground contact time: First frame of touchdown to last frame of toe-off.
Flight time: Toe-off of the previous step to touchdown of the current step.
Step frequency: 1 ÷ (contact time + flight time), in Hz.

Step quality (first 6 steps)

Speed at toe-off: Instantaneous speed at the toe-off of each step.
Toe-off thigh separation: Left knee – mid-hip – right knee angle at toe-off. Big shapes allow greater forces.
Touchdown knee separation: The same angle at touchdown. Negative when the swing knee is behind the stance knee.
Contact distance (braking angle): Angle between the line from the ground-contact toe to the mid-hip and the vertical from the mid-hip, at touchdown. Larger = foot lands further ahead of the hip.
Leg stiffness: Spring-mass model (Morin et al., 2005), in kN/m, using body mass and estimated leg length (both printed on the report). Not calculated for the first step.
Normative range: Average over the first six steps, compared with age, sex, sport and cohort norms.

05 · Motor preference

Acceleration profile: the four quadrants

Every Acc test is placed on a quadrant chart using two z-scores against the athlete's cohort: ground-contact time relative to flight time (horizontal) and step length relative to step rate (vertical). The quadrants come from James Wild and Neil Bezodis's research on sprint acceleration technique, so they apply directly to this test.

Reading the chart

Dashed squares mark 0.5, 1.5 and 2.5 SD from the cohort average.
L2 norm = distance from the centre: how distinct the athlete's profile is.
Bubble = session average, coloured by maximum speed vs cohort. Left and right legs are plotted separately to show asymmetry.

Relative risks (RR) are from 85 professional rugby players followed for seven seasons; * marks a statistically significant difference. Use them to individualise risk reduction, not as a diagnosis.

06 · Practitioner value

First-step speed, measured properly

Explosiveness

How fast an athlete builds speed from still: the "first-step" quality that decides short sprints in team sport.

Real game demands

Most sprints in team sport are short (5–20 m), so a 10–20 m test reflects what athletes actually do.

Strength and power

The first strides depend on force production at the hip, knee and ankle; step quality shows how well that force is used.

Training response

Re-test to see the effect of strength, power and sprint-technique work on each of the first six steps.

Pair with the Fly test

Acc results limited but Fly results good points to force production; the opposite points to elastic, reactive speed.

Return to play

Compare each step and each leg with the athlete's own baseline before clearing them for full sprinting.

07 · Support

FAQs

Which test tag should I use?

VM-Acc-10-m, VM-Acc-20-m, VM-Acc-10-yd or VM-Acc-20-yd, matching the distance you set up. If you don't see a tag, email support@vuemotion.com.

Why does the back foot need to be in view?

The clock starts when the back foot leaves the ground. If it is out of frame, the start can't be detected accurately.

Why are step-quality metrics missing from my report?

They need video recorded at 50 fps or more. Record at 4K/60 fps.

Can the athlete run in either direction?

Yes. Left-to-right and right-to-left are both supported.

Are CSV exports and APIs available?

CSV/Excel export is available for Enterprise and Academy users, and API access for Enterprise users.

Faude O, Koch T, Meyer T. Straight sprinting is the most frequent action in goal situations in professional football. Journal of Sports Sciences. 2012;30(7):625–631.
Gronwald T, Klein C, Hoenig T, et al. Hamstring injury patterns in professional male football (soccer): a systematic video analysis of 52 cases. British Journal of Sports Medicine. 2022;56(3):165–171.
Wild JJ, Bezodis NE. Sprint acceleration technique is associated with lower limb injury epidemiology in professional male Rugby Union players: a seven-season analysis. Journal of Science and Medicine in Sport. 2026. doi:10.1016/j.jsams.2026.05.009
Morin JB, Edouard P, Samozino P. Technical ability of force application as a determinant factor of sprint performance. Medicine & Science in Sports & Exercise. 2011;43(9):1680–1688.
Kenneally-Dabrowski CJB, Brown NAT, Lai AKM, Perriman D, Spratford W, Serpell BG. Late swing or early stance? A narrative review of hamstring injury mechanisms during high-speed running. Scandinavian Journal of Medicine & Science in Sports. 2019;29(8):1083–1091.
Bramah C, Tawiah-Dodoo J, Rhodes S, Elliott JD, Dos'Santos T. The Sprint Mechanics Assessment Score: a qualitative screening tool for the in-field assessment of sprint running mechanics. American Journal of Sports Medicine. 2024;52(6):1608–1616.
Butler RJ, Crowell HP, Davis IM. Lower extremity stiffness: implications for performance and injury. Clinical Biomechanics. 2003;18(6):511–517.
Davis JJ, Gruber AH. Leg stiffness, joint stiffness, and running-related injury: evidence from a prospective cohort study. Orthopaedic Journal of Sports Medicine. 2021;9(5).
Morin JB, Dalleau G, Kyröläinen H, Jeannin T, Belli A. A simple method for measuring stiffness during running. Journal of Applied Biomechanics. 2005;21(2):167–180.