Here’s a WordPress post_tag description for “膝蓋” (Xīgài – Knee) in Traditional Chinese, considering SEO and usefulness:

**Description Options (Choose the best fit for your blog’s style and target audience):**

**Option 1 (Simple and Descriptive):**

> **解釋：** 膝蓋，指腿部的關節，連接大腿和小腿。這個標籤涵蓋關於膝蓋的所有內容，包括疼痛、護理、運動、解剖學知識，以及常見膝部問題的討論和治療方法。
>
> **English Translation (for background, not to be added to the description itself):** Explanation: Knee, referring to the joint of the leg, connecting the thigh and lower leg. This tag covers all content related to the knee, including: pain, care, exercise, anatomical knowledge, and discussions and treatments of common knee problems.

**Option 2 (Focusing on Content Type – Good for a Health/Medical Blog):**

> **解讀：** 您可以在這裡找到關於膝蓋健康和醫療的各種資訊。探討膝蓋相關的疼痛症狀、受傷原因、康復策略、手術選項、復健方法，以及如何預防膝蓋問題。涵蓋健康知識、專業建議，以及最新的膝蓋護理研究。
>
> **English Translation (for background):** Analysis: Here you can find various information about knee health and medical treatment. We explore knee-related pain symptoms, causes of injury, recovery strategies, surgical options, rehabilitation methods, and how to prevent knee problems. Covers health knowledge, professional advice, and the latest research on knee care.

**Option 3 (Adding a bit more flavor – Good for a broader audience):**

> **关键词：** 膝盖，關節，疼痛，受伤，康复，運動，護理，健康。探索有關膝蓋的所有資訊。從生活方式的建議，到如何減輕膝蓋疼痛，以及詳細的解剖學知識，您都能在這裡找到。了解如何保持膝蓋健康，改善生活品質。
>
> **English Translation (for background):** Keywords: Knee, joint, pain, injury, recovery, exercise, care, health. Explore all information about the knee. From lifestyle advice to how to relieve knee pain, and detailed anatomical knowledge, you can find it all here. Learn how to keep your knees healthy and improve your quality of life.

**Option 4 (Concise and SEO-focused):**

> **內容：** 膝蓋相關資訊，包括膝蓋疼痛、受傷、康復、護理、運動，以及常見疾病的治療方法。
>
> **English Translation (for background):** Content: Information related to the knee, including knee pain, injury, recovery, care, exercise, and treatments for common diseases.

**Key Considerations when choosing:**

* **Your Blog’s Focus:** Is it medical, fitness, general health, or something else? Choose the description that best aligns with your content.
* **Target Audience:** Consider their level of knowledge and what they’re likely searching for.
* **Keywords:** All options include relevant keywords (knee, pain, recover, etc.)
* **Length:** Make sure it’s within the WordPress character limit (it’s usually plenty long, but consider it!)

**How to use this in WordPress:**

1. **In the WordPress Dashboard:** Navigate to either the “Tags” section (in the Posts Menu) or when you edit a specific post and add the tag.
2. **Edit “膝蓋” Tag:** Click on the tag name to edit it, or add a new one.
3. **Enter Description:** Find the “Description” or “Tag Description” field (depending on your theme) and paste your chosen description.
4. **Update/Save:** Save the tag.

This description will make your “膝蓋” tag more informative and help your audience understand what kind of content will be found under it! Remember to choose the best fit for *your* specific blog!