Clinical Proof

Clinical research has shown EMS technology to be an effective treatment for quadriceps atrophy, which is associated with almost all knee injuries and that the use of KNEEHAB® can significantly reduce post-operative rehabilitation time.

Prof. H.H. Pässler
Sven Fiel (MS)
Centre for Knee and Foot Surgery
Sports Traumatology ATOS Clinic Centre
Heidelberg, 691115 Germany

Background: Rehabilitation interventions following surgical repair of the anterior cruciate ligament (ACL) are key determinants affecting patient return to usual activity levels. Studies show that neuromuscular electrical stimulation (NMES) can counteract loss of strength in the quadriceps and is a beneficial enhancement to traditional forms of therapy. This study compared the effect of adding traditional NMES or garment-integrated NMES to a standard post-surgery rehabilitation program. In both cases the NMES was superimposed on isometric voluntary contractions.

Study Design: Prospective, controlled, randomised, single-blind study in patients undergoing rehabilitation following anterior cruciate ligament reconstruction.

Methods: Ninety-six patients who underwent surgical reconstruction of the anterior cruciate ligament were randomly assigned to one of three post-surgery rehabilitation treatment groups. All patients followed a standard rehabilitation program of voluntary exercises. Additionally, the PS group, (n=29), trained with a traditional NMES device and the KH group (n=33) trained with a garment integrated NMES device with multipath activation. The additional training for the PS and KH groups consisted of twenty-minute quadriceps muscle stimulation sessions, three times per day, five days per week for twelve weeks. The control group CO, (n=34) performed only volitional maximum quadriceps muscle contraction according to the same timed training session. Strength of the extensors and the flexors of the injured and uninjured legs at 90°/sec and 180°/sec, along with functional tests of proprioception, were assessed at baseline and at 6 weeks, 12 weeks and 6 months post operatively.

Results: There was convincing evidence (p<0.001 in all cases) of a significant Treatment and Time effect, with no Treatment by Time interaction, for all physical responses. With respect to the primary outcome measures, (knee extensor strength, single leg hop and shuttle run tests) the KH group achieved significantly (P<0.001) better results at each time point compared to the PS and CO groups. Extensor strength of the KH group at speeds of 90°/sec and 180°/sec increased by 30.2% and 27.8% respectively between pre-operative and 6 month follow-up points. The corresponding changes for PS were 5.1% and 5% while for CO they were 6.6% and 6.7% respectively. The mean single leg hop score of the KH group improved by 50% between the 6-week and 6 month follow up visits, while the corresponding changes for the PS and CO groups were 26.3% and 26.2% respectively. In nearly all tests, the KH group demonstrated a clear advantage at the 6-week follow up point, which was maintained, but not increased, for the remainder of the study.

Conclusions and Clinical Relevance: This study suggests that intensive NMES superimposed on voluntary contractions, combined with a standard rehabilitation program is effective in accelerating recovery. The benefit of adding the EMS component appears to accrue in the first 6 weeks post-operatively.