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Test protocol · Vertical deceleration · Entry

Single-Leg Drop & Holdstep off a 30 cm box · land on one leg · hold

1Record2Upload3See the results
Why it matters: landing on one leg is where many knee injuries happen. How much the knee bends and whether it stays aligned on landing show how well the athlete absorbs force (Hewett et al., 2005; Leppänen et al., 2017). A simple hold can't show the angles.VueMotion measures the landing from the side and the front for each leg.

The athlete steps off a 30 cm box, lands on the test leg on the marker and holds still for 2–3 seconds. Two iPhones, side and front, synced with Controller-Capture, record 3–5 valid trials per leg.

2
synced iPhones: side + front
30 cm
box
3–5
valid trials per leg
PhaseSet
Why it matters

Land, absorb, hold. VueMotion measures each step.

Every trial gives you three layers, for each leg.

ABS
Absorption

Knee flexion at initial contact, peak knee flexion and knee-flexion excursion.

ALN
Alignment

Frontal-plane projection angle (FPPA) of the knee at initial contact and peak.

HLD
Stability

Valid 2-second hold, time to stable hold, and hip and pelvis control.

01

Performance monitoring

Is landing control improving?

  • Trend Track each limb across sessions.
  • Hold Count clean holds and time to stabilise.
  • Both limbs Compare left and right every time.
02

Performance improvement

What should we coach?

  • Absorption Knee flexion at contact and peak show how force is absorbed.
  • Alignment Knee alignment (FPPA) shows control from the front.
  • Strategy Trunk and hip position show compensations.
03

Injury risk management

Who lands in a way that loads the knee?

  • Knee alignment Greater frontal-plane knee motion in landing tasks is linked to ACL injury risk (Hewett et al., 2005).
  • Stiff landing Little knee flexion means less force absorption (Leppänen et al., 2017).
  • Asymmetry A limb that lands differently is a flag to investigate.
04

Return to play / rehab

Is the injured limb ready for more load?

  • Progression A good early-stage task before higher-impact tests.
  • Baseline Compare with the uninjured limb and pre-injury results (Wellsandt et al., 2017).
  • Quality Clear clean holds before progressing.
05

Benchmarking

How does the athlete compare?

  • Reference bands Compare angles with published reference ranges.
  • Cohort Use matched groups only.
  • Squad Screen whole groups quickly.
06

Scouting / screening

Who needs landing work first?

  • Fast screen A few trials per limb.
  • Flags Poor alignment or failed holds.
  • Objective Video angles instead of eye-balling.

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

01 · Setup

Box, marker and two cameras

Place a 30 cm box on a firm surface. Mark the landing spot just in front of the box. Centre both cameras on the landing marker.

PhaseSet
Side cameraFront cameraLanding marker / line
C1

Sagittal camera

Side-on, perpendicular to the landing marker, about 3 m away, lens about 1 m high, on a tripod. Full body in frame through the whole landing and hold.

C2

Frontal camera

In front of the landing marker, facing the athlete, about 3 m away at the same height. Both knees and feet clearly visible. Record both phones in sync with Controller-Capture.

Capture at 60–120 fps, Auto-FPS off, iPhone 11 or newer. Camera distances and height are a starting point; keep them the same between sessions.

02 · Capture

Record in a few minutes

1

Equipment

2 iPhones, tripods, a 30 cm box and tape for the landing marker.

2

Scene

Box on a firm surface; mark the landing spot in front of it.

3

Cameras

Side and front cameras centred on the marker, synced with Controller-Capture.

4

Tag + record

Choose the athlete, the test tag and the test leg, then record 3–5 trials per leg.

5

Upload

Upload the original files and submit the AI request.

Athlete

  • Warm up and practise a few landings
  • Stand on the test leg on the box
  • Step off (don't jump), land on the same leg on the marker
  • Hold still for 2–3 s; the trial is invalid if the other foot touches down or they hop

Camera settings

  • HD at 60 or 120 fps on iPhone (or 4K 120 fps on GoPro)
  • Auto-FPS off (Settings → Camera → Record Video)
  • Fixed tripod, 1× lens, no zoom or panning
  • Do Not Disturb on, Auto-Lock never

Scene & upload tips

  • Start recording before the athlete moves; stop after the hold or the last rep
  • No one else in either camera's view
  • Shorts or tights that show the knees help the front view
  • Upload original files from the app; avoid AirDrop or messaging apps
03 · Outputs

What you get after upload

Absorption

Knee flexion at initial contact, peak knee flexion and excursion.

Alignment

FPPA at initial contact and peak.

Stability

Valid hold (pass/fail), time to stable hold, corrections.

Hip & pelvis

Hip and pelvic control, reported descriptively.

Left vs right

Both legs side by side.

Progress

Every metric across sessions.

Linking landing to injury risk

Thresholds marked as reference values come from the literature and are not validated injury-risk cut-offs for every population; compare limbs and track change over time.

MetricLink to performance or injuryEvidence

Performance linked to performance   Prospective linked to future injury in a cohort study   Mechanistic linked to tissue loading in lab studies   Practice coaching rationale

Metric definitions

Landing
Knee flexion at initial contact (°)
Knee angle (side view) when the foot first touches down.
Peak knee flexion (°)
Largest knee bend after landing.
Knee-flexion excursion (°)
Peak minus initial contact; small values suggest a stiff landing.
FPPA (°)
2D frontal-plane angle of hip–knee–ankle alignment; reported as a 2D projection, not full 3D valgus.
Stability
Valid hold
Stays on the test leg for 2 s with no extra steps or touch-down.
Time to stable hold (s)
Time from landing until the athlete is still.
Hip and pelvis control
Pelvic drop and hip position, reported descriptively (a pelvic tilt angle can also be generated).
04 · Practitioner value

A simple, early-stage landing screen

Low impact

Suits early rehab and entry-level clients.

Two views

Side and front angles from one landing.

Clear rules

Pass/fail hold plus angles.

Fits the battery

Progress to the single-leg CMJ, LESS and hop tests.

05 · Support

FAQs

Step off or jump off?

Step off, so the drop height is the same every time.

How many trials?

3–5 valid trials per leg.

Can I add a force plate?

Yes; time-to-stabilisation and landing-force asymmetry from a force plate can be reported alongside, time-aligned to the video.

Are CSV exports and APIs available?

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

  1. Hewett TE, Myer GD, Ford KR, et al. Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study. American Journal of Sports Medicine. 2005;33(4):492–501.
  2. Leppänen M, Pasanen K, Kujala UM, et al. Stiff landings are associated with increased ACL injury risk in young female basketball and floorball players. American Journal of Sports Medicine. 2017;45(2):386–393.
  3. Munro A, Herrington L, Carolan M. Reliability of 2-dimensional video assessment of frontal-plane dynamic knee valgus during common athletic screening tasks. Journal of Sport Rehabilitation. 2012;21(1):7–11.
  4. Herrington L, Munro A. Drop jump landing knee valgus angle; normative data in a physically active population. Physical Therapy in Sport. 2010;11(2):56–59.
  5. Wellsandt E, Failla MJ, Snyder-Mackler L. Limb symmetry indexes can overestimate knee function after anterior cruciate ligament injury. Journal of Orthopaedic & Sports Physical Therapy. 2017;47(5):334–338.