Seventy-seven patients with 84 operated limbs participated in a follow-up examination on an average of about six years after the resection of the first rib for thoracic outlet syndrome (TOS). Forty-two limbs (50%) were totally asymptomatic one month after the operation and remained so for at least half a year postoperatively. In the follow-up examination, 31 limbs were still asymptomatic, whereas 11 limbs had the same symptoms as before the operation. Of the nine patients with recurrent TOS (two with bilateral resection), seven were women and two were men. These nine patients were on average 38 years old (range = 19 to 51 years) and their jobs consisted of monotonous desk work. Seven of 11 stumps of the first rib were subluxated disclosed by the cervical rotation-lateral-flexion test. The occurrence of a subluxated stump of the first rib in the group of asymptomatic patients was far lower, only 3% (p less than .001). Of the 42 patients with persistent problems, a subluxated stump was encountered in seven (17%). Results of this follow-up examination suggest that monotonous desk work is an important factor causing kinesiologic abnormalities in the thoracic aperture. This abnormal kinesiology contributes to the recurrence of TOS symptoms even after the resection of the first rib.