Why Concreters Commonly Develop Knee and Lumbar Pain

Sustained Kneeling and the Knee

Of all the occupational risk factors for knee pathology, sustained kneeling on hard surfaces is the most mechanically consequential and the most preventable. Concreting requires extensive kneeling during formwork installation, screeding, finishing, and surface treatment — often on recently poured or curing concrete that provides neither softness nor thermal insulation. The patella, patellar tendon, quadriceps tendon, and prepatellar and infrapatellar bursae are the structures most directly loaded by sustained kneeling, and each responds differently to the compressive, tensile, and frictional forces of the kneeling position.

The prepatellar bursa — located between the anterior patella and the overlying skin — is subject to direct compressive loading every time the worker kneels. Repeated microtrauma to the bursal wall produces prepatellar bursitis (the "housemaid's knee" of traditional anatomy) — a painful, fluctuant swelling over the patella that makes further kneeling acutely painful. In the longer term, the patellar tendon is loaded in a compressive position when the knee is in deep flexion under load — the position required for the low kneeling used during concrete finishing — driving the reactive tendinopathy at the patellar tendon-bone junction that is among the most common chronic knee complaints in concreters. The menisci are additionally loaded by the compressive and rotational forces of kneeling in asymmetric positions, and meniscal tears — both acute and degenerative — are significantly more prevalent in occupations involving sustained kneeling than in the general population.

Lumbar Loading: The Time-Pressure Factor

Concreting is a time-critical activity. Concrete begins to set within a defined window after pouring, and the entire finishing and preparation sequence must be completed within that window regardless of the physical cost to the workers involved. This time pressure is a significant and often overlooked risk amplifier: workers adopt whatever posture most efficiently accomplishes the task, rather than the posture that minimises mechanical loading. Bending and reaching across a freshly poured slab — rather than kneeling or adopting a supported squat — is faster; it is also a direct application of sustained lumbar flexion under asymmetric load, with all the posterior annular consequences that entails.

The manual handling demands of concreting compound this: carrying bags of concrete mix (20–40 kg), operating vibrators and power trowels, and managing heavy formwork all add episodic high-load events to an already elevated continuous loading baseline. The lumbar spine in an active concreter sustains a daily loading well in excess of what disc nutrition and recovery can sustain indefinitely, and the accelerated disc degeneration documented in construction tradespeople reflects this accumulated daily deficit.

Management

Prepatellar bursitis in the acute phase requires load reduction and, where bursitis is infected (septic bursitis from skin abrasion), medical assessment. Chronic patellar tendinopathy responds to isometric loading in the pain management phase, progressing to heavy slow resistance isotonic loading as pain settles. Lumbar disc pathology follows the staged rehabilitation approach described for other heavy trades: manual therapy to restore segmental mobility, progressive stabilisation exercise to rebuild multifidus function, and occupational modification to reduce the time-pressured postures that drive continued disc loading. Advocacy for adequate knee pad provision and structured use of mechanical aids for concrete vibration and handling is a legitimate component of occupational health management in this trade.