Clinical Research

Clinical research explains that improving your motion balances multiple factors biomechanically. A fundamental biomechanics’ principle was studied in the 1990’s, now known as the Total End Range Time (TERT) method.  TERT informs how ERMI devices can effectively stretch and treat scar tissue. In landmark research, a study of shoulders advanced our understanding today, and established a benchmark for effective treatments of motion loss. 

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Reference Methods Findings Conclusion

Papotto & Mills
January 2012

Journal of Orthopaedic Nursing

Randomized Control Trial  - Knee patients

Head to Head study – ERMI High Intensity Stretch (HIS) Flexionater® vs. Low Intensity  Stretch (LIS) Competitive Device

Knee Flexion and outcome scores differ when comparing HIS versus LIS devices.

HIS devices had significantly  greater gains in range of motion and significantly higher WOMAC outcome scores

Treatment of postoperative arthrofibrosis with a HIS home mechanical therapy device was more effective and resulted in significantly improved outcomes when compared to LIS devices.

Yenchak, Wilk, Arrigo, Simpson, and Andrews

September 2011

Orthop Sports Phys Therapy 2011;41(9):675-686. doi:10.2519/ jospt.2011.3453 

Case report

Criteria-Based Management of an Acute Multi-structure Knee Injury in a Professional Football Player.

The patient was cleared to begin sport-specific activity 7 months after major multistructure reconstructive knee surgery in 2007, and then went to play mid season 2008, for the next 2 seasons as a starter in the NFL.

The purpose of this case report is to present a criteria-based approach to the postoperative management of a multi-ligament knee injury. 

This case report highlights the clinical decision-making process and management involved in an acute multiple ligamentous knee injury/reconstruction.

ERMI Knee Extensionater® was prescribed as part of clinical treatment. No monetary support from Company was involved.

Uhl & Jacobs 2011 ; 

Journal of Arthroplast;  

Comparative Laboratory Study

In this laboratory-based study, the amount of torque applied by physical therapists during mobilization techniques used to increase range of motion was compared to that of common home exercises and three types of mechanical therapy (dynamic splint, static progressive stretch brace, and a high-intensity stretch ERMI device).

ERMI high-intensity devices provided loads (53 N-m) to the joint that more closely replicate the force applied by a physical therapist (68 N-m), whereas low-intensity devices including dynamic splints (7.6 N-m) and SPS devices (10.4 N-m) provide loads similar to those provided by common home exercises (6.2 to 12.4 N-m).

The results demonstrated that home exercises, a dynamic splint, and an SPS brace demonstrated lower peak torque than the torque applied by PTs or an ERMI device.

Dempsey et al.

American Journal of Physical Medicine and Rehabilitation

Retrospective Cohort

Retrospective Cohort

Shoulder adhesive capsulitis (frozen shoulder) patients

American Shoulder and Elbow Society Standardized Shoulder

Assessment Form (ASES) scores and external rotation and abduction were recorded before and after the rehabilitation protocol and were compared between the two groups – high and low irritability / sensitivity of shoulder pain.

For both groups, external rotation and abduction of the involved shoulder significantly increased from pre- to post-treatment with the ERMI Shoulder Flexionater ®.

There were no differences between the groups in either external rotation (P = 0.71) or abduction (P = 0.46).

The authors concluded that a total end range time-maximizing rehabilitation protocol is a safe, effective treatment option for patients with frozen shoulder, whether the patient had high or low irritability in the shoulder.

Wolin et al. 2010;  

Annual Meeting, American Academy of Orthopaedic Surgeons

Retrospective Case Series

Postoperative shoulder adhesive capsulitis


Patients with postoperative adhesive capsulitis were treated with consecutive periods of PT, and PT with high-intensity home mechanical therapy with the ERMI Shoulder Flexionater®.

Passive shoulder abduction, internal and external rotation were recorded. Following a period of PT alone, the addition of mechanical therapy resulted in significant gains (p<.05) in shoulder abduction (134.9° to 158.3°), external rotation (55.9° to 79.4°), and internal rotation (32.0° to 41.3°).

The authors concluded that adjunctive high-intensity mechanical therapy with the ERMI Shoulder Flexionater ® resulted in significantly greater gains in shoulder abduction, internal, and external rotation.

Stephenson et al. 2010;  

Current Medical Research Opinion;

Retrospective Cohort 

Knee arthrofibrosis; age < 65 years

In the largest study of arthrofibrosis known, a comparison of arthrofibrosis patients treated with a low-intensity stretch device;  a high-intensity stretch ERMI device, and physical therapy alone was conducted to measure knee-attributable medical costs and the risks of re-operation, re-injury, and re-hospitalization

Patients treated with HIS mechanical knee therapy demonstrated significantly reduced rates of re-hospitalization which corresponded to reduced knee-attributable medical costs.

By applying force replicating that applied during physical therapy on a daily basis in the patient’s home, use of ERMI high-intensity devices resulted in significant savings to the healthcare system of more than $9,000 per patient when compared to patients treated with low-intensity splints.

Dempsey et al. 2010;

Sports Medicine Arthroscopy, Rehab Therapy & Technology

Retrospective Cohort

Knee arthrofibrosis patients

In a retrospective study Dempsey et al. evaluated the efficacy of the ERMI Knee Extensionater ®® in groups of worker’s compensation and non- worker’s compensation patients, and found no difference in the gains in knee extension between worker’s compensation and non-compensation patients (p = 0.56).

It has been well established in the literature that worker’s compensation patients demonstrate significantly worse outcomes following knee surgery and/or rehabilitation than non-compensation patients.

The authors concluded that the adjunctive use of HIS mechanical therapy is an effective treatment option for patients with knee flexion contractures, regardless of whether the patient is being treated as part of a worker’s compensation claim or not.

Branch, et al. 2003;

Amer Journal of Orthopaedics

Prospective Case Series

Knee arthrofibrosis patients 

The authors followed a series of knee arthrofibrosis patients who added home mechanical therapy with ERMI Knee Flexionater® device after failure with physical therapy alone.

Over the course of this therapy, mean knee flexion progressed from 70.8° to 130.6°, with 31 patients (91.2%) regaining functional flexion. In addition to reducing the risk of reoperation in this series of patients, the motion gains were maintained at a mean follow-up of 4.7 years.

The authors concluded that a home mechanical therapy program will reduce the need for surgical management of loss of knee flexion.