Acute effects of medium-frequency electrical energy transfer (TECAR) and transcutaneous electrical nerve stimulation (TENS) on pain and flexibility in athletes with an acute hamstring injury: A randomized controlled trial

This study compared the acute effects of electrical energy transfer (TECAR) and transcutaneous electrical stimulation (TENS) on pain and flexibility after a hamstring injury. Young athletes received either a 20 ​min TECAR (<i>n</i> = ​24) or TENS (<i>n</i> ​= ​26) session within 5 days following a hamstring injury, while the control (CON, <i>n</i> ​= ​25) group was instructed to rest. Visual analogue scale (VAS), functional Assessment Scale for Acute Hamstring Injuries (FASH), straight leg raise test (SLR), and sit-and-reach scores (STR) were obtained prior to, immediately, 24, and 48 ​h after therapy. Group differences were detected after therapy in VAS and FASH scores (<i>p</i> ​< ​0.05). Compared to pre-therapy measurements, VAS scores showed a greater decrease in the TECAR group (-38.75% to -63.33%) than in the TENS group (-16.67% to -25.00%) and both were greater than in the CON group (-2.81% to -9.81%) (<i>p</i> ​< ​0.05). The TECAR group improved FASH scores (28.57%-48.21%) more than the TENS group (15.89%-27.79%) and both groups more than the CON group (0%-8.33%) (<i>p</i> ​< ​0.05). The increase in SLR and STR was greater in the TECAR group (6.26%-13.96%) than in the TENS (1.72%-9.53%) and CON groups (0%-3.03%). These results suggest that in the acute phase of hamstring injury, the use of TECAR and, to a lesser extent, TENS may relieve pain symptoms and bring some improvements in flexibility more than instructing patients to rest.