---
title: "body_segment_length"
description: "Measurement of the distance between two points of surface anatomy."
---

Measurement of the distance between two points of surface anatomy.

**Purpose.** To record the measurement of the distance between two points of surface anatomy.

## Source

| Model | Leg | Role |
|---|---|---|
| `openEHR-EHR-OBSERVATION.body_segment_length.v1` | openEHR | defines this table |

## Columns

| Column | Type | Null | Description | Source |
|---|---|---|---|---|
| `id` | `uuid primary key` | no | Primary key. | — |
| `form_id` | `uuid` → [`form`](/docs/tables/form) | no | The form this entry was recorded on. | — |
| `form_block_id` | `uuid` | yes | The block within the form, when the entry is bound to one. | — |
| `event_type` | `text` | yes | null represents any_event | — |
| `body_segment_name`<br />`body_segment_name_code`<br />`body_segment_name_system`<br />`body_segment_name_valueset_id` | coded text<br />`text`, `text`, `text`, `text` | yes | Body segment name | `/data[at0001]/events[at0002]/data[at0003]/items[at0004]` |
| `laterality`<br />`laterality_code`<br />`laterality_system`<br />`laterality_valueset_id` | coded text<br />`text`, `text`, `text`, `text` | yes | Laterality | `/data[at0001]/events[at0002]/data[at0003]/items[at0005]` |
| `length_magnitude`<br />`length_units` | quantity<br />`numeric`, `text` | yes | Length | `/data[at0001]/events[at0002]/data[at0003]/items[at0008]` |
| `comment` | `text` | yes | Comment | `/data[at0001]/events[at0002]/data[at0003]/items[at0009]` |
| `confounding_factors` | `text` | yes | Confounding factors | `/data[at0001]/events[at0002]/state[at0010]/items[at0011]` |
| `body_position`<br />`body_position_code`<br />`body_position_system`<br />`body_position_valueset_id` | coded text<br />`text`, `text`, `text`, `text` | yes | Body position | `/data[at0001]/events[at0002]/state[at0010]/items[at0031]` |
| `measurement_method` | `text` | yes | Measurement method | `/protocol[at0014]/items[at0027]` |
| `measurement_origin`<br />`measurement_origin_code`<br />`measurement_origin_system`<br />`measurement_origin_valueset_id` | coded text<br />`text`, `text`, `text`, `text` | yes | Measurement origin | `/protocol[at0014]/items[at0029]` |
| `measurement_endpoint`<br />`measurement_endpoint_code`<br />`measurement_endpoint_system`<br />`measurement_endpoint_valueset_id` | coded text<br />`text`, `text`, `text`, `text` | yes | Measurement endpoint | `/protocol[at0014]/items[at0033]` |

## Constraints

```sql
check ((body_segment_name_code is null and body_segment_name_system is null and body_segment_name_valueset_id is null) or (body_segment_name is not null and body_segment_name_code is not null and body_segment_name_system is not null and body_segment_name_valueset_id is not null))
check ((laterality_code is null and laterality_system is null and laterality_valueset_id is null and laterality is null) or (laterality is not null and laterality_code is not null and laterality_system is not null and laterality_valueset_id is not null))
check ((length_magnitude is null and length_units is null) or (length_magnitude is not null and length_units is not null))
check (length_magnitude is null or (length_units = 'cm' and length_magnitude >= 0) or (length_units = '[in_i]' and length_magnitude >= 0) or (length_units = 'mm' and length_magnitude >= 0))
check ((body_position_code is null and body_position_system is null and body_position_valueset_id is null) or (body_position is not null and body_position_code is not null and body_position_system is not null and body_position_valueset_id is not null))
check ((measurement_origin_code is null and measurement_origin_system is null and measurement_origin_valueset_id is null) or (measurement_origin is not null and measurement_origin_code is not null and measurement_origin_system is not null and measurement_origin_valueset_id is not null))
check ((measurement_endpoint_code is null and measurement_endpoint_system is null and measurement_endpoint_valueset_id is null) or (measurement_endpoint is not null and measurement_endpoint_code is not null and measurement_endpoint_system is not null and measurement_endpoint_valueset_id is not null))
```

## Unique

- `form_block_id`

## References

| Columns | Target | On delete |
|---|---|---|
| `form_id` | [`form`](/docs/tables/form) | cascade |
| `form_id, form_block_id` | [`form_block`](/docs/tables/form_block) | cascade |
| `body_segment_name_valueset_id, body_segment_name_code, body_segment_name_system, body_segment_name` | [`valueset_code`](/docs/tables/valueset_code) | restrict |
| `laterality_valueset_id, laterality_code, laterality_system, laterality` | [`valueset_code`](/docs/tables/valueset_code) | restrict |
| `body_position_valueset_id, body_position_code, body_position_system, body_position` | [`valueset_code`](/docs/tables/valueset_code) | restrict |
| `measurement_origin_valueset_id, measurement_origin_code, measurement_origin_system, measurement_origin` | [`valueset_code`](/docs/tables/valueset_code) | restrict |
| `measurement_endpoint_valueset_id, measurement_endpoint_code, measurement_endpoint_system, measurement_endpoint` | [`valueset_code`](/docs/tables/valueset_code) | restrict |

## Referenced by

- [`body_segment_length_measuring_device`](/docs/tables/body_segment_length_measuring_device) via `body_segment_length_id`
- [`body_segment_length_structured_origin`](/docs/tables/body_segment_length_structured_origin) via `body_segment_length_id`
- [`body_segment_length_structured_endpoint`](/docs/tables/body_segment_length_structured_endpoint) via `body_segment_length_id`

## Indexes

- `body_segment_length_form_id_idx` on `form_id`

## Child tables

3 tables hang off `body_segment_length`, one row per repetition.

### `body_segment_length_measuring_device`

Child table — one row per repetition, deleted with its parent.

| Column | Type | Null | Description | Source |
|---|---|---|---|---|
| `id` | `uuid primary key` | no | Primary key. | — |
| `body_segment_length_id` | `uuid` → [`body_segment_length`](/docs/tables/body_segment_length) | no | — | — |
| `position` | `integer` | no | Order of this row within its parent, from zero. | — |
| `device_id` | `uuid` | no | Measuring device | `/protocol[at0014]/items[at0015]` |

#### Unique

- `body_segment_length_id, position`
- `body_segment_length_id, device_id`

#### References

| Columns | Target | On delete |
|---|---|---|
| `body_segment_length_id` | [`body_segment_length`](/docs/tables/body_segment_length) | cascade |
| `device_id` | [`device`](/docs/tables/device) | no action |

#### Indexes

- `body_segment_length_measuring_device_device_id_idx` on `device_id`

### `body_segment_length_structured_origin`

Child table — one row per repetition, deleted with its parent.

| Column | Type | Null | Description | Source |
|---|---|---|---|---|
| `id` | `uuid primary key` | no | Primary key. | — |
| `body_segment_length_id` | `uuid` → [`body_segment_length`](/docs/tables/body_segment_length) | no | — | — |
| `position` | `integer` | no | Order of this row within its parent, from zero. | — |
| `anatomical_location_id` | `uuid` | no | Structured origin | `/protocol[at0014]/items[at0030]` |

#### Unique

- `body_segment_length_id, position`
- `body_segment_length_id, anatomical_location_id`

#### References

| Columns | Target | On delete |
|---|---|---|
| `body_segment_length_id` | [`body_segment_length`](/docs/tables/body_segment_length) | cascade |
| `anatomical_location_id` | [`anatomical_location`](/docs/tables/anatomical_location) | no action |

#### Indexes

- `body_segment_length_structured_origin_anatomical_locatio_620ef3` on `anatomical_location_id`

### `body_segment_length_structured_endpoint`

Child table — one row per repetition, deleted with its parent.

| Column | Type | Null | Description | Source |
|---|---|---|---|---|
| `id` | `uuid primary key` | no | Primary key. | — |
| `body_segment_length_id` | `uuid` → [`body_segment_length`](/docs/tables/body_segment_length) | no | — | — |
| `position` | `integer` | no | Order of this row within its parent, from zero. | — |
| `anatomical_location_id` | `uuid` | no | Structured endpoint | `/protocol[at0014]/items[at0035]` |

#### Unique

- `body_segment_length_id, position`
- `body_segment_length_id, anatomical_location_id`

#### References

| Columns | Target | On delete |
|---|---|---|
| `body_segment_length_id` | [`body_segment_length`](/docs/tables/body_segment_length) | cascade |
| `anatomical_location_id` | [`anatomical_location`](/docs/tables/anatomical_location) | no action |

#### Indexes

- `body_segment_length_structured_endpoint_anatomical_locat_2708d2` on `anatomical_location_id`

## Value sets

| Value set | Codes |
|---|---|
| `org.openehr::openEHR-EHR-OBSERVATION.body_segment_length.v1/body_position` | 3 |
| `org.openehr::openEHR-EHR-OBSERVATION.body_segment_length.v1/body_segment_name` | 12 |
| `org.openehr::openEHR-EHR-OBSERVATION.body_segment_length.v1/laterality` | 2 |