Shoulder-neck disorders are a major concern for society. Trapezius myalgia, or pain from the descending part of the trapezius muscle, is frequent in occupational groups engaged with repetitive and monotonous low-force work tasks. Previously, conflicting results have been reported regarding muscle strength reductions in persons with shoulder-neck disorders compared to unaffected persons. It can be hypothesized that muscle strength in persons with trapezius myalgia may primarily be affected during the latter part of shoulder abduction where the descending part of the trapezius muscle contributes to external rotation of the scapula. PURPOSE: To evaluate isometric and isokinetic shoulder muscle strength in females with trapezius myalgia compared to a group of healthy female controls. METHODS: 13 females clinically diagnosed with trapezius myalgia (TM; 45 ± 6 yrs, 166 ± 6 cm, 72 ± 14 kg) and 9 healthy female controls (CON; 45 ± 8 yrs, 168 ± 5 cm, 68 ± 9 kg) were tested in a Biodex dynamometer. The subjects performed maximal voluntary isometric shoulder muscle contractions at 3 static positions (35°, 75° and 115° abduction in the scapular plane). Furthermore, peak torque was measured during isokinetic shoulder abduction at slow and fast concentric (60, 180°s−1) and slow eccentric contraction (−60°s−1). RESULTS: Isometric torque at 35° and 75° was similar between the two groups (TM vs CON: 38 vs 37 Nm and 38 vs 40 Nm, respectively). However, above the horizontal plane, i.e. at 115°, TM showed lower levels of torque compared to CON (31 vs 37 Nm, P <0.05). Furthermore the ratio between torque at the more vs. less abducted shoulder joint position (i.e. torque at 115°/35°) were significantly lower in TM. Also, isokinetic peak torque was significantly lower in TM especially during maximal eccentric muscle contraction (42 vs 49 Nm, P <0.05). CONCLUSION: The present results demonstrate that maximal muscle strength is specifically reduced during the latter range of motion of shoulder abduction in females with trapezius myalgia. This may reflect specific force inhibition of the trapezius muscle which contributes to external scapular rotation during the more abducted shoulder joint position. During dynamic contraction eccentric muscle strength appears to be most profoundly affected. These results may have important implications for rehabilitation strategies aimed to alleviate trapezius myalgia.