> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplift.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Pelvis Acceleration Time

> Time from pelvis initiation (start of rotation, also known as launch event) to peak pelvis angular velocity. This measures the acceleration phase of the pelvis during the swing.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** seconds
* **Column Name:** pelvis\_acceleration\_time
* **Aggregation:** mean
* **Precision:** 2
* **Calculation:** Peak pelvis velocity time - Pelvis initiation time
* **Typical Range:** 0.22 – 0.62 s
* **Optimal Direction:** Middle — moderate values are optimal

## Description

Pelvis acceleration time measures the duration of the pelvis acceleration phase from the start of rotation (launch) to peak angular velocity, indicating the time period for lower body power generation.

## Normative Ranges

Percentile distributions by competition level from the 2026 Q1 dataset; the optimal range spans the 25th–75th percentiles.

| Population         | Optimal Range (25th–75th) | 10th | 25th | 50th | 75th | 90th |
| ------------------ | ------------------------- | :--: | :--: | :--: | :--: | :--: |
| Youth              | 0.38 – 0.65 s             | 0.27 | 0.38 | 0.49 | 0.65 | 1.47 |
| High School        | 0.31 – 0.61 s             | 0.20 | 0.31 | 0.45 | 0.61 | 1.52 |
| College            | 0.18 – 0.60 s             | 0.17 | 0.18 | 0.37 | 0.60 | 0.86 |
| Professional       | 0.18 – 0.54 s             | 0.15 | 0.18 | 0.23 | 0.54 | 0.75 |
| Broad (All Levels) | 0.22 – 0.62 s             | 0.17 | 0.22 | 0.42 | 0.62 | 0.89 |

## Use Cases

* Acceleration phase analysis
* Power generation efficiency
* Lower body mechanics assessment