According to the Integrative Veterinary Care Journal «the spring of the retractable leash causes a continuous pull that generates a degree of stress in the cervical region... And, when the dog gets to the
end of the retractable leash, the sudden stop and jerk causes additional force... This causes spasms and inflammation in the inter-scapular region and
nerve and energy meridian pathways are
affected or impinged by tight muscles.»