KASportsFormer: Kinematic Anatomy Enhanced Transformer for 3D Human Pose Estimation on Short Sports Scene Videos

1Graduate School of Informatics, Nagoya University, 2RIKEN
An overview of our proposed KASportsFormer.

An overview illustration of our anatomy feature utilization. Anatomy structures are extracted and composed into bones and limbs, which are interacted in a multimodality strategy

Abstract

Recently, transformer based approaches have demonstrated convincible performance in solving real-world 3D Human Pose Estimation problems. Albeit these excellent approaches achieve fruitful results on benchmark datasets, they tend to fail on sports videos whose movements are more complicated than daily life actions.

Moreover, due to the difficulty in capturing 3D sports pose data and the fact that critical actions in a sports game often appear in moments of time (e.g. shooting), current 3D pose estimation models appear to lack the analyzing ability when encountered with short sports videos.

In this paper, we present the Bone extractor (BoneExt) and Limb fuser (LimbFus) modules, which decomposes bone length and directions from joint input and exploits potential kinematic dependencies of sports actions through a multimodality manner. Through composing an anatomy feature into a Spatio-temporal Transformer, we propose KASportsFormer, which exhibits an improved capability of comprehending underlying human sports pose with temporal limitations.

We evaluate our methods through two representative sports scene datasets: SportsPose and WorldPose. Our proposed method achieves state-of-the-art results with MPJPE errors of 58.08 mm and 34.37 mm, respectively.

Pipeline

We frist extract the bone expression inside the original coordinates.

bone extractor

We then compose extracted bones into various limbs, including biological ones and hypothetical ones.

limb fuser

We treat the extractd bone and reconstructed limb as different context and thus we study their interations with a multimodality manner.

multimodality processing

The overall proprocessing pipeline of our proposed methods:

overall processing pipeline

Experiments

We compare our proposed method with two sports motion centered datasets.

We first compare our proposed method with concurrent 3D Human Pose Estimation methods on SportsPose Datasets.

SportsPose dataset quantitative comparisons

We also apply a comparison on each action category within the SportsPose Dataset.

SportsPose dataset action based quantiative comparisons

To demonstrate the capability of sports applications, we additionally adopt a Soccer Game focused human pose dataset called WorldPose, and compare our proposed method with other works.

WorldPose dataset quantitative comparisons

Experiments on different configurations of our proposed method.

Experimetns on different parameters of our LimbFus module.

Visualization

Qualitative comparisons of our KASportsFormer with MotionAGFormer and D3DP on activities of SportsPose with detected inputs.

Visualization.

The gray skeleton is the ground truth 3D pose. The blue skeleton represents the estimated 3D pose result. The red dashed line indicates the incorrect regions of the compared methods, and the blue dashed line represents the couterparts of our proposed method.

Demo

BibTeX

If you find our work useful, please cite the paper

@misc{yin2025kasportsformer,
      title={KASportsFormer: Kinematic Anatomy Enhanced Transformer for 3D Human Pose Estimation on Short Sports Scene Video}, 
      author={Zhuoer Yin and Calvin Yeung and Tomohiro Suzuki and Ryota Tanaka and Keisuke Fujii},
      year={2025},
      eprint={2507.20763},
      archivePrefix={arXiv},
      primaryClass={cs.CV},
      url={https://arxiv.org/abs/2507.20763}, 
}

More of Our Works

You can also check out our concurrent sports-centered human pose analysis works.

AthletePose3D (AP3D) is a novel dataset for monocular 3D human pose estimation in sports biomechanics, designed to capture high-speed, high-acceleration movements. Alongside the raw dataset, we also provide a training-ready version prepared for 2D and 3D pose estimation modeling, including both preprocessed annotations and AP3D fine-tuned model parameters.

AutoSoccerPose is a pipeline aimed at semi-automating 2D and 3D pose estimation and posture analysis. While achieving full automation proved challenging, we provide a foundational baseline, extending its utility beyond the scope of annotated data.

Pseudo-label based unsupervised fine-tuning of a monocular 3D pose estimation model for sports motions is an accurate and convenient sports motion capture system based on un-supervised fine-tuning.

FS-Jump3D is the first figure skating jump dataset that includes both 3D pose data and video data from 12 viewpoints. The jump data were captured using the markerless motion-capture system (Theia3D, Theia) by positioning 12 high-speed cameras (Miqus Video, Qualisys) on the ice skating rink.

Acknowledgement

Our work refers to and builds on the following repositories and datasets:

We appreciate the authors for their invaluable codes release and we also thank the authors' contribution to sports pose data creation