Why Compression Socks Are Most Important After 21 Kilometers: New Half-Marathon Research

Ankle injuries are among the most common and frustrating complications for long-distance runners, often occurring when fatigue compromises the body's ability to sense and respond to foot position changes. Breakthrough research reveals that compression socks for running can provide crucial defense against these injuries by maintaining ankle proprioceptive capabilities – your body's internal GPS system for joint position.

Understanding Proprioception and Running Injuries

Proprioception is your body's ability to sense joint position and movement without looking. For runners, ankle proprioception is especially critical. Your ankle constantly makes micro-adjustments during running, responding to surface texture changes, small obstacles, and body weight shifts.

As running distance increases and fatigue appears, this proprioceptive ability naturally begins declining. This deterioration in joint position sense is one reason ankle injuries often occur during the final stages of long runs when runners are fatigued.

The Research

Researchers conducted a detailed study with 20 well-trained half-marathon runners. Each participant completed two identical 21-kilometer runs on a treadmill – one with compression socks and another with regular running socks.

The study divided each runner into three 7-kilometer segments and tested ankle proprioception after each segment.

Key Findings: When Compression Makes a Difference

Results revealed a striking pattern:

Early Distance (7 km): At the 7-kilometer mark, there was no difference in ankle proprioception between runners wearing compression socks and those with regular socks.

Mid Distance (14 km): Even at the halfway point, proprioceptive capabilities remained similar between both groups.

Late Distance (21 km): Here compression socks showed their protective effect. After completing the full half-marathon distance, runners wearing compression socks showed significantly better ankle proprioception compared to those with regular socks.

Connection to Injury Prevention

Maintaining ankle proprioception at longer distances has direct implications for injury risk. Research consistently shows that impaired proprioception is a major risk factor for ankle injuries.

When your ankle's ability to sense its position deteriorates due to fatigue, you're more prone to:

• Awkward landing on uneven surfaces
• Delayed protective muscle responses when your foot begins rolling inward
• Missing subtle balance adjustments

By maintaining better proprioceptive control during the final stages of long runs, compression socks can help runners avoid ankle injuries.

Why Compression Socks Help Proprioception

The mechanism for this protective effect likely relates to enhanced sensory feedback that medical compression socks provide:

• Increased skin sensation: Graduated pressure stimulates mechanoreceptors in the skin
• Improved muscle awareness: Compression can enhance awareness of muscle length and tension
• Reduced muscle oscillation: Decreasing unnecessary muscle vibrations during foot strikes
• Improved blood flow: Better circulation helps maintain optimal functioning of sensory receptors

Practical Applications for Runners

These findings suggest that compression socks may be especially valuable for:

• Long training runs: Runners preparing for half-marathons and marathons regularly completing runs exceeding 15 kilometers
• Trail runs: Those running on technical terrain where ankle injuries are more common
• Injury-prone runners: Athletes with a history of ankle sprains
• Race day strategy: Half-marathon and marathon runners can use compression socks to maintain proprioceptive control during critical final race stages

Important Findings

The research discovered that proprioceptive benefits appear only after significant distance accumulation. For shorter runs or early stages of longer runs, proprioceptive advantages may not be apparent.

About the Research:

This research was conducted by Chang, Fu, Wu and colleagues to determine the effect of graduated compression socks on ankle proprioception and examine the relationship between fatigue and ankle proprioception measurements in half-marathon runners at sequential intervals during a 21-km run.