Variability in Flexibility of Dominant and Non-Dominant Shoulder Joints among Healthy Young Adults

Abstract

Background: The shoulder joint comprises of a large humerus head and smaller glenoid fossa. It is an incongruous
ball and socket type of joint. The joint has sacrificed its articular congruency for more range of motion. The
dominant upper limb is involved in activities of daily living (ADLs) such as self-grooming, eating, lifting objects
etc. Range of motion of the shoulder may be influenced by various factors and also dominance.
Objective: The study aims to identify variation in flexibility of the shoulder joint in dominant and non-dominant
upper limbs and to identify the various factors influencing it.
Method: This cross-sectional study included young healthy adults of either gender between the age group of 18-
26 yrs. Participants with history of shoulder injuries, dislocations, generalised hypermobility were excluded from
participation. The total sample size was 169 with 37 males and 132 females. The participants performed Apley’s
scratch test for flexibility measurement bilaterally for both dominant and non-dominant shoulder.
Result: The total number of sample size was 169 out of which 37 were males and 132 were females. Data from
169 participants (165 right-hand dominant and 4 left-hand dominant) was analysed, and it was discovered that
the dominant shoulder showed more flexibility than the non-dominant side. There was no gender difference in
shoulder flexibility. It showed that the age was inversely proportional to flexibility of the shoulder joint. BMI
shows to have a negative influence on the joint flexibility.
Discussion: This study showed the dominant side shoulder to have more positive values according to the Apley’s
scratch test compared to the non-dominant side. The flexibility values showed negative correlation with BMI.
Conclusion: Flexibility in the dominant shoulder joint is more compared to the non-dominant joint. BMI influences
the flexibility of the joint. The shoulder flexibility decreases with age. Gender doesn’t seem to have significant
variation in the shoulder joint flexibility.