Table 2 Scorings system Jump-landing Technique (JLS-system)

Maintaining 'balance'

- Loss of balance

Lifting one foot or toes of both feet due to falling.

Observe complete jump

Loss of balance present or not

Loss of balance not present or doubt: 0

Loss of balance present: 1

- Centre of gravity displacement

At first foot contact:

Perpendicular through incisura jugularis

At maximal knee flexion determine the position of incisura jugularis (left/right) compared to perpendicular

Displacement not present or doubt: 0

Displacement left or right: 1

Landing with 'both feet at the same time'

Not simultaneous:

obviously 2 contact times of the feet visible

Observe complete jump

Simultaneous landing present or not

Simultaneous landing present or doubt: 0

Simultaneous landing not present: 1

'Muscular control' during landing

Presence of eccentric control during landing, capacity to lower the body in a controlled manner (no side movements of the knee, no sudden stops)

Observe complete jump

Muscular control present or not

Muscular control present or doubt: 0

Muscular control not present: 1

'Genu varum' - 'Genu valgum' take-off

Malalignement:

valgus or varus position

At maximal knee flexion:

perpendicular from SIAS to ankle (middle of malleoli)

- Take-off

No varum or valgum:

perpendicular goes through centre of patella

Perpendicular through patella or doubt: 0

Patella lateral from the perpendicular:

(1 = varum)

Patella medial from the perpendicular:

(2 = valgum)

'Genu varum' - 'Genu valgum' landing

Malalignement:

valgus or varus position

At maximal knee flexion:

perpendicular from SIAS to ankle (middle of malleoli)

- Landing

No varum or valgum:

perpendicular goes through centre of patella

Perpendicular through patella or doubt: 0

Patella lateral from the perpendicular:

(1 = varum)

Patella medial from the perpendicular:

(2 = valgum)

'Position of feet'

Feet at shoulder width.

At maximal knee flexion:

Perpendicular trough centre of shoulders.

Perpendicular goes trough centre of malleolus internus and externus

Perpendicular through centre of malleoli or doubt: 0

Perpendicular not through centre of malleoli: 1

'Distance between knees' compared between initial contact and maximal knee flexion

Distance between knees at maximal knee flexion, 80-110% of distance between knees at initial contact.

Distance between knees at first foot contact and distance between knees at maximal knee flexion.

Range of 80%-110% difference.

Between 80%-11%: 0

Not between 80%-110%: 1

Hyperpronation - Hypersupination feet

Take-off

Inside or outside movement of the malleoli compared to starting position.

Observe complete jump

- Takeoff

Compare position feet with starting position.

Hyperpronation or -supination not present or doubt: 0

Hyperpronation or supination present: 1

Hyperpronation - Hypersupination feet

landing

Inside or outside movement of the malleoli compared to starting position.

Observe complete jump

- Landing

Compare position feet with starting position.

Hyperpronation or -supination not present or doubt: 0

Hyperpronation or supination present: 1

Side view

(right and left)

Criteria

Description

Observation

Measurement

Score

Knee angle

- First foot contact

- Maximal knee flexion

Knee angle at first foot contact

Knee angle at maximal knee flexion

Ankle between trochanter major - caput fibulae (tractus iliotibialis) -

mallolus externus

Degrees:

Hip angle

- First foot contact

- Maximal knee flexion

Knee angle at first foot contact

Knee angle at maximal knee flexion

Angle between trunk - trochanter major - caput fibulae (tractus iliotibialis)

Degrees:

Ankle angle

- First foot contact

- Maximal knee flexion

Knee angle at first foot contact

Knee angle at maximal knee flexion

Angle between caput fibulae (tractus iliotibialis) - malleolus externus - parallel with sole of foot

Degrees:

'shoulders above knees'

Position at maximal knee flexion

Perpendicular through centre of shoulder (humerus head)

Perpendicular through caput fibula: 0

Perpendicular not through caput fibula: 1

'knees not further than toes'

Position at maximal knee flexion

Perpendicular through centre of knees

Perpendicular not further than toes: 0

Perpendicular further than toes: 1

'forefoot landing and rolling to heel'

Forefoot landing and rolling to heel

Observe complete jump

Pattern present or not

Pattern present or doubt: 0

Pattern not present: 1

Arm swing

Obvious arm swing that contributes to the jump height

Observe complete jump

Arm swing present or not

Arm swing present: 0

Arm swing not present: 1