Reference; https://mbp-japan.com/jijico/articles/32376/
Modified and translated by CFJA
What Causes Katakori (Shoulder Stiffness)?
The Clinical Research Division’s Katakori Committee of the Japan Society of Acupuncture and Moxibustion (JSAM) investigated the condition from a variety of perspectives. According to sources such as the Comprehensive Medical Dictionary, katakori is defined as:
“A subjective sense of discomfort, spontaneous pain, or mild movement-induced pain in the neck, upper scapular region, scapula, or interscapular area. On physical examination, abnormal muscle tension and the presence of tender or hardened points in these muscles can often be detected.”
However, despite extensive study, the committee was unable to identify a single definitive cause.
Based on over 40 years of clinical experience, katakori appears to arise from both mental fatigue and physical fatigue.
Here are some personal observations:
- Mental fatigue may stem from the uniquely Japanese cultural habit of reading the room (social anticipation and self-restraint)
- Physical fatigue may be associated with long working hours, which in turn cause chronic sleep deprivation
Table of Contents
(1) On Mental Fatigue
Japanese culture is known for its refined sense of omotenashi, or thoughtful hospitality. While this attentiveness is admirable, excessive mental activity can lead to poor circulation around the shoulders, resulting in muscle stiffness.
In modern society, computer-based work has become a major contributing factor to mental strain and associated shoulder tension.
(2) On Physical Fatigue
The Japanese are often described as highly diligent. As a result, working hours tend to be long, and vacation time is rarely taken. This has led to Japan having the shortest average sleep duration among developed countries.
Lack of sleep also interferes with liver recovery. Since the liver plays a role in muscular function, its fatigue can impact the recovery of muscles around the shoulders, leading to stiffness and pain.
Physical Signs and Variations
- Katakori caused by mental fatigue may not be detectable through touch. In people who are emotionally or socially drained, the shoulders often feel heavily burdened, and may also be painful even without muscular hardness.
- Katakori caused by physical fatigue, on the other hand, presents with noticeably hardened muscles. After extended physical work, one may feel tightness or pressure in the shoulders and naturally want to massage or stretch the area.
In reality, many people experience a combination of both mental and physical fatigue, meaning that the nature of the stiffness may vary from day to day.
In addition to fatigue, underlying medical conditions or physical trauma may also be responsible for shoulder stiffness in some cases.