Mechanical Stretching Devices (LLPS / Static Progressive / Serial Stretch)

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.

Policy thresholds & functional ROM quick facts

Subacute period>= 3 weeks and <= 4 months after injury or surgery

Initial authorization period for LLPSUp to 4 months

Hallux limitus post-op timingDevice provided within two months after bunionectomy or cheilectomy

Functional shoulder abduction128° of shoulder abduction (functional ROM reference)

Functional shoulder cross-body abduction116° (functional ROM reference)

Functional shoulder external rotation90° external rotation with abduction of 59° (functional ROM reference)

Functional shoulder internal rotation102° internal rotation with 0° abduction (functional ROM reference)

Functional wrist range38° wrist flexion and 40° wrist extension (functional ROM reference)

Functional knee flexion110° of flexion (functional ROM goal for ADLs)

Knee ROM abnormalExtension deficit 6°-10° or flexion deficit 16°-25° vs noninvolved knee

Knee ROM severely abnormalExtension deficit >10° or flexion deficit >25° vs noninvolved knee

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

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

Required Documentation & Provider Actions

Prior Authorization

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

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.

Coding

Static progressive stretch device HCPCS codesHCPCSCovered

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.

Dynamic adjustable device HCPCS codesHCPCSCovered

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.

1–10 of 21

1/3

Serial Stretch Devices - example HCPCS billing designationHCPCS

E1399

Durable medical equipment, miscellaneous (used as classification for serial stretch devices in policy text)

Replacement / miscellaneous codesHCPCSCovered

E1821	Replacement soft interface material/cuffs for bi-directional static progressive stretch device.
E1399	Durable medical equipment, miscellaneous.

Type of service / Place of servicemixed

DME	Type of Service: Durable Medical Equipment.
Outpatient/Home	Place of Service.

Billing Rule

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

Billing Rule

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

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.

Evidence highlights (selected trials and summaries)

Quality of evidence summaryOverall evidence quality low to very low; limited/small RCTs and observational studies with short follow-up; insufficient to determine net health outcome for many devices/indications

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.

Device must be an appropriate dynamic adjustable or static progressive stretch device described by HCPCS E18xx codes as listed

Indication related to joint contracture, post-traumatic or post-surgical stiffness, adhesive capsulitis, arthrofibrosis, or other loss of motion supported by literature references

Revision History

2009-03-01Original Effective Date

Original Effective Date March 2009.

2023-01-01Revised

Policy revised January 2023.

2025-06-01Review / RenewalLatest

Annual Review and Policy Renewed in June 2025 (policy history notes Annual Review and Policy Renewed).