Mechanical Stretching Devices (LLPS / Static Progressive / Serial Stretch)
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Defines medical necessity, investigational indications, required documentation, and evidence rationale for mechanical stretching devices (low-load prolonged-duration stretch/dynamic splinting, static progressive stretch, and serial stretch devices) for treatment of limited joint range of motion following injury, surgery, or other conditions.
Policy revised January 2023; review date noted June 2025.
Policy history shows Annual Review and Policy Renewed in June 2025 with no explicit clinical changes in this fragment.
Coverage Summary
This policy addresses coverage of mechanical stretching devices (LLPS/dynamic splints, static progressive stretch, and serial/patient-actuated serial stretch) for limited joint range of motion after injury, surgery, or other causes. It is CURRENT with last review June 2025 and revisions noted January 2023. Key coverage thresholds: LLPS devices may be authorized in the subacute period (≥3 weeks and ≤4 months after injury or surgery) as an adjunct to PT/OT or when meaningful functional limitation persists or other therapy has failed; the initial authorization period is up to 4 months and continued coverage requires documented improvement after that period. For hallux limitus after bunionectomy or cheilectomy, devices may be provided if supplied within two months after surgery. Static progressive and serial stretch devices have separate investigational determinations described elsewhere in the policy.
Medically Necessary Criteria — LLPS (Low-Load Prolonged Stretch)
Low-Load Prolonged-Duration Stretch (LLPS) Devices - Medically Necessary Criteria
LLPS devices may be considered medically necessary for use on the knee, elbow, wrist, or finger in any of the following clinical settings:
ANY of the following
A. Addition to PT/OT in subacute/post-op period
- Used as an addition to physical or occupational therapy in the subacute injury or post-operative period
- Individual has signs and symptoms of persistent joint stiffness or contracture
- Initial authorization period: up to 4 monthsUp to 4 months
- If improvement demonstrated after initial period, may continue as long as improvement continues to be demonstrated
B. Subacute period with meaningful functional limitation and failed other therapy
- In subacute injury or post-operative period (>=3 weeks and <=4 months after injury or surgery)
- Limited range of motion poses a meaningful functional limitation as judged by the physician
- Has not responded to other therapy (including physical or occupational therapy)
- Initial authorization period: up to 4 monthsUp to 4 months
- If improvement demonstrated after initial period, may continue as long as improvement continues to be demonstrated
C. Acute post-operative period after additional surgery to improve ROM
- In the acute post-operative period for individuals who have undergone additional surgery to improve the range of motion of a previously affected joint
- Initial authorization period: up to 4 monthsUp to 4 months
- If improvement demonstrated after initial period, may continue as long as improvement continues to be demonstrated
D. Individuals unable to benefit from standard PT/OT due to inability to exercise
- Unable to benefit from standard physical or occupational therapy modalities because of an inability to exercise
- Initial authorization period: up to 4 monthsUp to 4 months
- If improvement demonstrated after initial period, may continue as long as improvement continues to be demonstrated
LLPS Devices - Hallux Limitus (Great Toe)
Medically necessary indication for hallux limitus following specific surgery
ALL of the following
- Persistent joint stiffness of the hallux limitus following bunionectomy or cheilectomy
- Device provided within two months after surgeryWithin 2 months after surgery
LLPS Devices - Not Medically Necessary After 4 Months Without Improvement
If criteria not met regarding improvement after trial period
Investigational / Not Medically Necessary
Investigational / Not Medically Necessary - LLPS
LLPS devices are investigational when any of the following apply:
ANY of the following
- Knee, elbow, wrist, or finger not meeting the medically necessary criteria above
- Persistent joint stiffness of the hallux limitus not meeting the above criteria
- For treatment of the shoulder and ankle
- For treatment of conditions related to chronic joint stiffness or chronic fixed contractures caused by: cerebral palsy; long term lack of motion in the joint; neuromuscular disease; plantar fasciitis; rheumatoid arthritis; stroke
Static Progressive Stretch Devices - Investigational
Static progressive stretch (SPS) devices are considered investigational for all indications
Serial Stretch Devices (E1399) - Investigational
Patient-actuated serial stretch devices are investigational for all indications
Required Documentation & Provider Actions
Initial trial period and demonstration of improvement
Initial trial period: initial authorization may be granted for up to 4 months. Continued coverage beyond the initial trial requires documented clinical improvement in ROM and function. If no meaningful improvement is demonstrated after the 4-month trial, discontinue device therapy.
Documentation required for medical necessity
Documentation required for medical necessity: submit the items below with the prior authorization or claim to support coverage.
- Physician prescription/order specifying device type, intended use, and HCPCS code (E1399 may be used when appropriate for serial stretch devices).
- Office/therapy notes documenting the affected joint, date of injury or surgery, prior treatments and response, and functional limitations.
- Baseline and follow-up objective ROM measurements (with measurement dates) to demonstrate change over time.
- Treatment plan describing device usage regimen (hours per day or number/length of sessions depending on device type), duration, and measurable goals.
- Clinical indication and supporting literature or clinical rationale to justify medical necessity for this specific patient (attach relevant studies or clinical notes).
Prior conservative therapy
Prior conservative therapy should be documented. Patients generally must have failed or plateaued with appropriate physical or occupational therapy (commonly at least 6 weeks of documented therapy) unless there is a clear clinical reason that therapy is contraindicated or the patient is unable to participate.
Coding
| E1801 | Static progressive stretch/patient actualized serial stretch elbow device, extension and/or flexion, with or without range of motion adjustment, includes all components and accessories. |
| E1806 | Static progressive stretch wrist device, flexion and/or extension, with or without range of motion adjustment, includes all components and accessories. |
| E1811 | Static progressive stretch/patient actualized serial stretch knee device, extension and/or flexion, with or without range of motion adjustment, includes all components and accessories. |
| E1816 | Static progressive stretch/patient actualized serial stretch ankle device, flexion and/or extension, with or without range of motion adjustment, includes all components and accessories. |
| E1818 | Static progressive stretch forearm pronation/supination device, with or without range of motion adjustment, includes all components and accessories. |
| E1831 | Static progressive stretch toe device, extension and/or flexion, with or without range of motion adjustment, includes all components and accessories. |
| E1832 | Static Progressive stretch finger device, extension and/or flexion with or without range of motion adjustment, includes all components and accessories. |
| E1841 | Static progressive stretch/patient actualized serial stretch shoulder device, with or without range of motion adjustment, includes all components and accessories. |
| E1800 | Dynamic adjustable elbow extension and flexion device, includes soft interface material. |
| E1802 | Dynamic adjustable forearm pronation/supination device, includes soft interface material. |
| E1803 | Dynamic adjustable elbow extension only device, includes soft interface material. |
| E1804 | Dynamic adjustable elbow flexion only device, includes soft interface material. |
| E1805 | Dynamic adjustable wrist extension and flexion device, includes soft interface material. |
| E1807 | Dynamic adjustable wrist extension only device, includes soft interface material. |
| E1808 | Dynamic adjustable wrist flexion only device, includes soft interface material. |
| E1810 | Dynamic adjustable knee extension and flexion device, includes soft interface material. |
| E1812 | Dynamic knee, extension/flexion device with active resistance control. |
| E1813 | Dynamic adjustable knee extension only device, includes soft interface material. |
| E1399 | Durable medical equipment, miscellaneous (used as classification for serial stretch devices in policy text) |
| DME | Type of Service: Durable Medical Equipment. |
| Outpatient/Home | Place of Service. |
Use appropriate HCPCS codes and descriptions
Report the specific HCPCS E18xx code that matches the device provided. When a listed code does not apply, E1399 (Durable medical equipment, miscellaneous) may be used per the coding guidance.
- Use the exact E18xx HCPCS code for the device (see policy HCPCS list)
- E1399 may be used for miscellaneous DME when appropriate
Coding note for serial stretch devices (E1399)
Serial stretch (patient-actuated / high-intensity) devices may be reported using E1399 per the policy coding section; include device-specific information on claims when using miscellaneous coding.
- If coding as E1399, include device model/name and description on the claim
Place of service / Type of service
Type of service and place of service should reflect durable medical equipment and the outpatient/home setting as appropriate when billing for these devices.
- Type of Service: DME
- Place of Service: Outpatient/Home
Evidence Summary
Overall quality of evidence is described as low to very low; available studies are small, heterogeneous, and have limited follow-up, leaving insufficient evidence to definitively establish net health benefit for many devices and indications. A Hayes HTA (May 2022) reviewed 23 studies (including 10 RCTs) and concluded that evidence is insufficient to demonstrate consistent benefit over standard physical therapy, though devices appear generally safe.
Key randomized trials include a small knee RCT (Papotto & Mills, 2012) where a high-intensity serial stretch (ERMI) device produced larger ROM gains and higher rates of achieving functional knee flexion (≥110°) versus a lower-intensity static progressive device after ~7 weeks. Shoulder RCTs (Ibrahim/Hussein series) showed greater short-term ROM with SPS plus PT versus PT alone but inconsistent effects on pain and function over longer follow-up. A 2024 RCT (Teytelbaum et al) of adhesive capsulitis enrolled 34 patients across three arms (HIS device, PT, combination); all groups improved ROM but sample size and reporting limit conclusions. An elbow RCT (Lindenhovius et al, 2012) found comparable improvements between SPS and dynamic splinting on most outcomes with some differences at specific time points.
A large retrospective claims analysis (Stephenson et al, 2010) reported fewer rehospitalizations and subsequent knee events in high-intensity stretch users versus low-intensity or no-device groups, but observational design limits causal inference. Systematic reviews and case series report ROM gains with dynamic splints and SPS devices but emphasize limited study quality and uncertain clinical significance; safety signals have been minimal across studies.
Mechanical stretching devices differ by mechanism and typical usage patterns: LLPS/dynamic splints use springs or elastic bands to deliver continuous low-load prolonged stretch (commonly worn 6–12 hours per day, often overnight or in multi‑hour daytime sessions). Static progressive stretch (SPS) devices use a crank/ratchet to hold and incrementally increase joint angle during repeated short sessions (typically 15–30 minutes per session, several times daily). Serial/patient‑actuated serial stretch (PASS/ERMI) devices use hydraulics to alternate higher‑intensity stretch and relaxation delivered in multiple brief daily sessions (examples: 6×10‑minute sessions).
Definitions
| Term | Definition |
|---|---|
| LLPS | Low-load prolonged-duration stretch (dynamic splinting) devices that provide continuous low-intensity tension via springs or elastic for prolonged periods (commonly 6–12 hours). |
| SPS | Static Progressive Stretch (SPS): devices that hold a joint in a set position and allow manual modification of angle via a crank/ratchet for repeated short sessions (typically 15–30 minutes) and allow incremental increases in tissue length via adjustable tension. |
| Serial Stretch / PASS | Patient-Actuated Serial Stretch (PASS) devices: use hydraulics to alternate periods of higher-intensity stretch and relaxation in multiple short sessions (high-intensity serial stretch). |
| Static progressive stretch device | Devices that allow incremental increases in tissue length via adjustable tension, often used in multiple short sessions per day; corresponds to HCPCS static progressive codes (E18xx). |
| Serial stretch / ERMI | High-intensity serial stretch devices (ERMI) that use hydraulics to alternate periods of high-intensity stretch and relaxation; often delivered in multiple brief daily sessions (examples: ERMI Knee Extensionator, Flexionator, Shoulder Flexionator). |
| Dynamic splint | Splint using springs or elastic bands to provide low-load prolonged stretch (elastic traction), typically worn many hours or overnight (commonly 6–12 hours/day). |
| DASH | Disabilities of the Arm, Shoulder and Hand questionnaire: a 30-item measure with scores from 0 (no disability) to 100 (most severe) used to assess upper limb function. |
| WOMAC | Western Ontario and McMaster University Osteoarthritis Index for hip and knee function and pain; used as a functional outcome measure in studies. |
| Dynamic adjustable device | Devices providing dynamic adjustable force or resistance to increase range of motion; corresponds to HCPCS E18xx dynamic adjustable codes (E1800, E1802, E1803, etc.). |
| LLPS (alternate name) | Dynamic splinting; low-load prolonged-duration stretch devices permitting active and passive motion via elastic traction and adjustable tension-controlled units worn during rest or sleep. |
| DME / Place of Service | Type of Service: Durable Medical Equipment (DME); Place of Service commonly Outpatient or Home. HCPCS miscellaneous code E1399 may be used for serial stretch devices when appropriate. |
Supplemental Coverage Notes
Coverage / Medical Necessity Criteria (part content not shown in this fragment)
Policy fragment provides codes and references; clinical criteria were in earlier parts of the document.
Revision History
Original Effective Date March 2009.
Policy revised January 2023.
Annual Review and Policy Renewed in June 2025 (policy history notes Annual Review and Policy Renewed).
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